Readers and authors alike will be pleased to know that the impact factor (IF) of OEM has risen to 2.817 in 2007, from 2.255 in 2006. (The IF is a bibliometric index which measures the citation frequency of articles contained in a journal, standardised according to its number of published, potentially citable articles.)

Objectives: To examine the burden of work-related injuries among immigrants to Canada compared to Canadian-born labour force participants.

Methods: Using data from the 2003 and 2005 Canadian Community Health Surveys (N = 99,115), two nationally representative population samples, we examined the risk of self-reported, activity limiting work-related injuries among immigrants with varying time periods since arrival in Canada. Models were adjusted for hours of work in the last 12 months as well as various demographic and work-related variables.

Results: Immigrant men in their first five years in Canada reported lower rates of activity limiting injuries compared to Canadian-born respondents. Surprisingly, the percent of injuries that required medical attention was much higher among recent immigrants compared to Canadian-born respondents, resulting in an increased risk of activity limiting injuries requiring medical attention among immigrant men, compared to Canadian-born labour force participants. No excess risk was found among female immigrants compared to Canadian-born female labour market participants.

Conclusions: Immigrant men in their first five years in Canada are at increased risk of work-related injuries that require medical attention. A similar risk is not present among immigrant women. Further, given differences in the number of activity limiting injuries requiring medical attention across immigrant groups, we believe this excess risk among immigrant men may be underestimated in the current data source. Future research should attempt to fully capture the barriers faced by immigrants in obtaining safe employment, the number of injuries that are sustained by immigrants while working, and the consequences of these injuries.

AIMS: To describe incident and recurrent work-related back injuries among a well-defined cohort of union carpenters, to describe the hazard function for each and associated risk factors, and to explore predictors of subsequent musculoskeletal back injury based on different definitions of the initial injury.

METHODS: We identified a dynamic cohort of 18,768 carpenters who worked in the State of Washington 1989-2003, their hours worked each month, and their work-related back injuries and medical claims for treatment including ICD9 codes. Using Poisson regression we calculated rates and rate ratios of incident and recurrent injury adjusting for age, gender, union tenure and type of carpentry work. Predictors of a subsequent musculoskeletal back injury were explored based on different definitions of the incident injury as were time periods of greatest risk following return to work.

RESULTS: Recurrent back injuries occurred at a rate 80% higher than initial injuries. Survival curves were significantly different for incident and recurrent injuries, but patterns of relative risk were similar. Individuals with greatest union tenure were at lowest risk likely reflecting a healthy worker effect or lower physical exposures with seniority. Individuals with long periods of work disability with their first injury were at particularly high risk of subsequent musculoskeletal injury when compared to those with no prior history (RR=2.3; 95% CI 2.0, 2.7), as were individuals with degenerative diagnoses (RR 2.0; 95% CI 1.5, 2.6). Risk for second injury peaked between 1000 and 1500 hours after return to work and then gradually declined.

CONCLUSIONS: Carpenters with long periods of work disability following back injury warrant accommodation and perhaps better rehabilitation efforts to avoid re-injury. Challenges to workplace accommodation and limited ability to clearly define readiness to return to work following injury demonstrate the need for primary prevention of back injuries through attention to engineering solutions among these carpenters involved in strenuous work.

Objectives: To determine whether sickness absence is a prognostic marker in terms of mortality among people with common chronic conditions.

Methods: Prospective occupational cohort study of 13 077 men and 4871 women aged 37 to 51 from the National Gas and Electricity Company, France. Records of physician-certified sickness absences over a 3-year period were obtained from employers' registers. Chronic conditions were assessed in annual surveys over the same period. The main outcome measure was all-cause mortality (803 deaths, mean follow-up after assessment of sickness absence, 13.9 years)

Results: In Cox proportional-hazard models adjusted for age, sex, socioeconomic position and co-morbidity, >28 annual sickness absence days vs no absence days was associated with an excess mortality risk among those with cancer (hazard ratio 5.4, 95% CI 2.2 to 13.1), depression (1.7, 1.1 to 2.8), chronic bronchitis/asthma (2.7, 1.6 to 4.6), and hypertension (1.6, 1.0 to 2.6). The corresponding hazard ratios for more than 5 long (>14 days) sickness absence episodes per 10 person-years vs no such episodes were 5.4 (2.2 to 13.1), 1.8 (1.3 to 2.7), 2.0 (1.3 to 3.2) and 1.8 (1.2 to 2.7), respectively. Areas under receiver-operating-characteristics curves for these absence measures varied between 0.56 and 0.73 indicating the potential of these measures to distinguish groups at high risk of mortality. The findings were consistent across sex, age and socioeconomic groups and in those with and without co-morbid conditions.

Conclusion: Data on sickness absence may provide useful prognostic information for common chronic conditions at the population level.

Objetive: To explore the relationship between occupations and specific occupational exposures and oesophageal cancer (OC) by histological type.

Methods: We conducted a multicentre hospital-based case-control study in two Mediterranean provinces of Spain. Occupational, sociodemographic and lifestyle information was collected from 185 newly diagnosed male esophageal cancer cases (147 squamous cell, 38 adenocarcinoma), and 285 frequency matched controls. Occupation was coded according to the Spanish National Classification of Occupations 1994. Occupational exposure to a selection of carcinogenic substances was assessed by the FINJEM Job Exposure Matrix. Odds Ratios were calculated by unconditional logistic regression adjusting for age, education, alcohol drinking and cigarette smoking.

Results: For the squamous cell variety, statistically significant associations were found for 'Waiters and bartenders' (OR=8.18, 95%CI 1.98 to 33.75) and 'Miners, shotfirers, stone cutters and carvers' (OR=10.78, 95%CI 1.24 to 93.7) in relation to other occupations. For the adenocarcinoma variety, statistically significant associations were observed for ‘Carpenters and joiners' (OR=9.69), 'Animal producers and related workers' (OR=5.61) and 'Building and related electricians': (OR 8.26) although these observations were based on a low number of cases. Regarding specific exposures, we found a statistically significant increase in risk of squamous cell OC for 'Ionizing radiation', and of adenocarcinoma, for high exposure to 'Volatile sulphur compounds' (OR=3.12) and 'Lead' (OR=5.30). For all histological types of OC combined, we found a three-fold increase in risk with a significant trend for asbestos exposure (OR= 3.46, 95%CI 0.99 to 12.10).

Conclusions: Our data suggest that occupational exposure does not seem to play a major role in OC in Spain. Some occupational exposures may specifically increase the risk of oesophageal squamous cell cancer or adenocarcinoma while other exposures may increase the risk of all OC types.

Context: Chrysotile from the mine in Balangero, Italy, is considered to be tremolite-free. In a cohort study of miners and millers only two pleural cancers were reported, a finding considered to contribute evidence that chrysotile has a low potency for inducing mesothelioma. However, follow-up ended in 1987 and white-collar workers and employees of sub-contractors were not studied.

Population and methods: To complete the case ascertainment, we searched the Registry of Malignant Mesotheliomas of Piedmont for records of cases among: mine employees; employees of subcontractors or of other firms transporting or refining Balangero asbestos, asbestos ore or mine tailings; individuals exposed to air pollution from the mine or living with mine employees; and individuals exposed to mine tailings from Balangero.

Results: We identified 4 new cases of pleural mesothelioma among blue-collar workers in the mine, in addition to the two reported in the cohort study. Thus, 6 mesotheliomas occurred, compared to 1.5 expected (p <0.01). We also identified 3 mesothelioma cases among white-collar employees at the mine, 5 in workers in the mine hired by subcontracting firms, and 3 among workers processing Balangero chrysotile outside the mine. Finally, 10 additional cases were identified due to non-occupational exposure or exposure to re-used mine tailings.

Conclusions: The cluster of 14 mesothelioma cases among workers who were active in the mine and 13 among other people exposed to Balangero chrysotile adds further evidence to the carcinogenicity of tremolite-free chrysotile.

Background: Ozone exposure is known to cause oxidative stress. We investigated the acute effects of ozone (O3) on lung function in the elderly, a suspected risk group. We then investigated whether genetic polymorphisms of antioxidant genes (heme oxygenase-1 [HMOX1] and glutathione S-transferase pi [GSTP1]) modified these associations.

Methods: We studied 1,100 elderly men from the Normative Aging Study whose lung function (forced vital capacity [FVC] and forced expiratory volume in one second [FEV1]) was measured every 3 years from 1995-2005. We genotyped the GSTP1 Ile105Val and Ala114Val polymorphisms and the (GT)n repeat polymorphism in the HMOX1 promoter, classifying repeats as short (n<25) or long (n≥25). Ambient O3 was measured continuously at locations in the Greater Boston area. We used mixed linear models, adjusting for known confounders.

Results: A 15 ppb increase in O3 during the previous 48 hours was associated with a 1.25% decrease in FEV1 (95% CI: -1.96%, -0.54%). This estimated effect was worsened with either the presence of a long (GT)n repeat in HMOX1 (-1.38%, 95% CI: -2.11%, -0.65) or the presence of an allele coding for Val105 in GSTP1 (-1.69%, 95% CI: -2.63%, -0.75). A stronger estimated effect of O3 on FEV1 was found in subjects carrying both the GSTP1 105Val variant and the HMOX1 long (GT)n repeat (-1.94%, 95% CI: -2.89%, -0.98%). Similar associations were also found between FVC and ozone exposure.

Conclusions: Our results suggest that ozone has an acute effect on lung function in the elderly, and the effects may be modified by the presence of specific polymorphisms in antioxidant genes.

Objectives To evaluate whether hourly changes in fine particle (PM_2.5, diameter<2.5 µm) exposure or outdoor particle concentrations are associated with rapid ischemic responses.

Methods Forty-one non-smoking elderly persons with coronary heart disease were followed up with biweekly clinic visits and air pollution measurements in Helsinki, Finland. The occurrence of ST segment depressions >0.1 mV was recorded during submaximal exercise test. Hourly variations in personal PM_2.5 exposure and outdoor levels of PM_2.5 and ultrafine particles (<0.1 µm) were recorded during 24-hrs before the clinic visit. Associations between particulate air pollution and ST segment depressions were evaluated using logistic regression.

Results Both personal and outdoor PM_2.5 concentrations, but not outdoor ultrafine particle counts, were associated with ST segment depressions. Odds ratio [per 10 µg/m3] for personal PM_2.5 concentration during the hour preceding clinic visit was 3.26, 95% CI: 1.07-9.99, and for 4-h average outdoor PM_2.5 2.47, 95% CI 1.05-5.85.

Conclusions Even very short-term elevations in fine particle exposure might increase the risk of myocardial ischemia. The mechanism is still open, but could involve changes in autonomic nervous control of heart.

Objectives: To estimate the prevalence and workplace consequences of adult attention-deficit/hyperactivity disorder (ADHD).

Methods: Ann ADHD screen was administered to 18-44 year-old respondents in ten national surveys in the WHO World Mental Health (WMH) Survey Initiative (n = 7075 in paid or self employment; response rate 45.9-87.7% across countries). Blinded clinical reappraisal interviews were administered in the US to calibrate the screen.. Days out of role were measured in the WHO Disability Assessment Schedule (WHO-DAS). Questions were also asked about ADHD treatment.

Results: An average of 3.5% of workers in the ten countries was estimated to meet DSM-IV criteria for adult ADHD (inter-quartile range: 1.3-4.9%). ADHD was more common among males than females and less common among professionals than other workers. ADHD was associated with a statistically significant 22.1 annual days of excess lost role performance compared to otherwise similar respondents without ADHD. No difference in the magnitude of this effect was found by occupation, education, age, gender, or partner status. This effect was most pronounced in Colombia, Italy, Lebanon, and the US. Although only a small minority of workers with ADHD ever received treatment for this condition, higher proportions were treated for comorbid mental-substance disorders.

Conclusions: ADHD is a relatively common condition among working people in the countries studied and is associated with high work impairment in these countries. This impairment, in conjunction with the low treatment rate and the availability of cost-effective therapies, suggests that ADHD would be a good candidate for targeted workplace screening and treatment programs.

Objectives: To examine the relationship between occupational exposures and spontaneous abortion in female veterinarians.

Methods: The Health Risks of Australian Veterinarians project (HRAV) was conducted as a questionnaire-based survey of all graduates from Australian veterinary schools during the 40-year period 1960-2000. Of 5,748 eligible veterinarians who were sent the questionnaires, 2,800 replied including 1,197 females (42.8%). The response rate was 59% of women veterinarians eligible to participate. The pregnancy of women was defined as the unit of analysis. We restricted analyses to pregnancies of those women who reported being employed when the pregnancy began and were working only in clinical practice. Of 1,355 pregnancies in total in the file, 940 pregnancies were eligible for the final analysis. Self-reported occupational exposures to anesthetic gases, x-rays, pesticides and long working hours in relation to spontaneous abortion were examined.

Results: In a multiple logistic regression controlling for the 12 potential confounders, there was more than two-fold significant increase (OR: 2.49 95% CI: 1.02, 6.04) in the risk of spontaneous abortion in women exposed to un-scavenged anesthetic gases for one or more hours per week. Veterinarians who reported performing more than five radiographic examinations per week had a statistically significant elevated risk of spontaneous abortion compared to those who performed less than five (OR:1.82 95%:CI:1.17-2.82). There was also about two–fold significant increased risk of spontaneous abortion in women who used pesticides at work (OR:1.88 95% CI: 1.18-3.00).

Conclusion: Female veterinarians, particularly those of childbearing age, should be fully informed of the possible reproductive effects of un-scavenged anesthetic gases, ionizing radiation and pesticide exposure and reduce their exposure by use of protective devices during pregnancy and the time when they are planning to become pregnant.

Objectives: To estimate excess mortality during heat waves and cold spells, and to identify vulnerable population groups, by age and cause of death.

Methods: The authors analyzed daily mortality from all non-accidental causes, cardio-vascular and respiratory mortality among all ages and in age group 75+, between January 2000 and February 2006 in Moscow, Russia. Mortality and displaced mortality during cold and heat waves were estimated using independent samples t-tests.

Results: Several discrete weather events during the period 2000-2006 were analyzed. Cumulative excess non-accidental mortality during the heatwave of 2001 was 33% (95% CI 20 to 46), or about 1200 additional deaths, with the share of short-term displaced mortality only about 10%. Mortality from coronary heart disease increased by 32% (16 to 48); cerebrovascular mortality increased by 51% (29 to 73), and respiratory mortality increased by 80% (57 to 101). In the age group 75+, corresponding mortality increments were consistently higher for all studied categories except respiratory deaths. An estimated 560 extra deaths were observed during the three heat waves of 2002, when non-accidental mortality increased by 8.5%, 7.8% and 6.1%, respectively. About 40% of these deaths were brought forward by only several days, thus bringing net mortality change down to 3.2% (0.8 to 5.5). The cumulative effects of the two cold spells of 2006 on mortality were significant only in the age group 75+, for which average daily mortality from all non-accidental causes increased by 9.9% (8.0 to 12) and 8.9% (6.7 to 11), resulting in 370 extra deaths; there was also a significant increase in coronary disease mortality and cerebrovascular mortality.

Conclusions: This study confirms that daily mortality does increase in Moscow during heatwaves and cold spells. A large proportion of excess deaths during heatwaves occur only a short time earlier than they would otherwise have done, but harvesting, or short-term mortality displacement, may be less significant for longer periods of sustained heat stress.

Objectives: To investigate the relation between male infertility and occupational exposures, particularly glycol ethers.

Methods: A case-referent study was designed in which men attending 14 fertility clinics in 11 centres across the United Kingdom in 1999-2002 were recruited following 12 months of unprotected intercourse and without a previous semen analysis. Cases were those with low motile sperm concentration (MSC) relative to the time since their last ejaculation (MSC<12x 106 for 3 days of abstinence). Referents were other men attending these clinics and meeting the inclusion criteria. A single semen sample was collected at the clinic and analysed at the andrology laboratory serving each hospital. Concentration was determined manually with motility assessed centrally from video recordings. Exposures and confounding factors were assessed from self completed and nurse-interviewer questionnaires, completed prior to the results of the semen analysis. The occupational histories were assessed for exposures relative to UK norms by a team of occupational hygienists blind to case status.

Results: Of 2118 men in employment at the time of the interview, 874 (41.3%) were cases. Work with organic solvents, particularly glycol ethers, in the 3 months before the first clinic visit was associated with the likelihood of low motile sperm count. Unadjusted odds ratios (OR) for moderate and high glycol ether exposure (compared with none) were 1.70 (95%CI 1.11-2.61) and 2.54 (95%CI 1.24 - 5.21). Adjustment for potential confounders (surgery to the testes, previous conception, wearing boxer shorts, drinking alcohol, employed in manual work) reduced the risk associated with glycol ether exposure: moderate OR=1.46 (95%CI 0.93-2.28) high OR=2.25 (95%CI 1.08-4.69). No other occupational risk factor was identified.

Conclusions: Glycol ether exposure was related to low motile sperm count in men attending fertility clinics. This suggests that, at the time of the study, glycol ethers continued to be a hazard for male fertility.

ABSTRACT

Objectives: The ability to measure temporal trends in disease incidence is important but valid methods are needed. We investigated UK trends during 1996-2005 in work-related skin and respiratory diseases including non-malignant pleural disease, asthma, mesothelioma and pneumoconiosis and the potential for bias when using surveillance systems for this purpose.

Methods: The volunteer reporters in three surveillance schemes were specialist physicians for skin diseases, respiratory diseases and occupational physicians respectively, who provided monthly reports of new cases of disease which they considered work-related. Poisson regression models were used to investigate variation by calendar year (trend), season and reporter characteristics. Separately, temporal patterns in the probabilities of non-response and zero reports were investigated. Annual changes in disease incidences were compared between reporter groups.

Results: There was little evidence of change in incidences of non-malignant pleural disease, mesothelioma, skin neoplasia and urticaria but falls were seen for contact dermatitis and pneumoconiosis. Although the direction of changes were similar across reporter groups, the magnitude of annual change in incidence was often not consistent: for occupational asthma, it was -1.9% (95% CI: -5.2,1.4) and -12.1% (95% CI:-19.5,-4.1) using respiratory and occupational physician reports respectively. Response rates were high (~85%) but non-response increased slightly with membership time, as did the probability of a zero return in some groups. Adjustment of results for presumed reporting fatigue led to an upward correction in some calendar trends.

Conclusions: Some estimated changes in incidence based on volunteer reporting may be biased by reporting fatigue; therefore apparent downward trends need to be interpreted cautiously. Differences in the population bases of the surveillance schemes and UK health service capacity constraints may also explain differences in trends found here. (277 words)

Background Several studies report a lower than expected mortality in lung cancer among workers exposed to organic dust. A recent study also reported a decreased risk for cancer at other sites.Objectives. To evaluate the mortality from lung and other cancer sites in cotton mill workers.

Material and methods A cohort of 3961 Italian cotton mill workers was divided in those working with carding (exposed to high levels of endotoxin-containing cotton dust) and other tasks, which generally have lower exposure. Standardized mortality ratios (SMR), with 95% confidence intervals (CI), were calculated using death rates of the regional general population as a reference. Cancer mortality was analyzed in relation to the length of employment in the two task groups. An internal analysis was also performed through Poisson regression.

Results Among workers in carding departments, lung cancer SMRs were 1.88 (CI=0.69-4.08), 1.01 (0.20-2.94), and 0.22 (0.00-1.24) respectively for <6, 6-12, and >12 years of employment (chi square for trend=5.45; p<0.05). A significant (p=0.04) trend was confirmed by Poisson regression. No reduced risks were found for other forms of cancer, nor for those working with other tasks.

Comments The results support previous reports that a high and prolonged exposure to cotton dust and other endotoxin containing organic dusts is related to a lower the risk of lung cancer. There was no indication of a reduced risk for other forms of cancer.

Background: Several studies have demonstrated associations between daily mortality and ambient particulate matter lessthan 2.5 microns in diameter (fine particles or PM2.5). Few, however, have examined the relative toxicities of PM2.5 constituents, including elemental and organic carbon (EC and OC), nitrates and transition metals. There is also little information about whether associations between PM2.5 constituents and mortality are modified by socioeconomic and demographic factors.

Aim: To examine associations of daily cardiovascular mortality with PM2.5 and 13 of its constituents after stratification by gender, race/ethnicity and education, using data from six California counties for 2000 through 2003.

Methods: The association of daily counts of cardiovascular mortality with PM2.5 components was analyzed using time-series regression analyses. Poisson models with natural splines were used to control for time-varying covariates such as season and weather. Separate models were run after stratification by gender, race/ethnicity (White, Hispanic, Black) and education (high school graduation or not). Models were run for each county and results were combined using random effects meta-analysis.

Results: Daily counts of cardiovascular mortality were associated with PM2.5 and several of its species including EC, OC, nitrates, sulfates, potassium, copper and iron. For many of these species, there were significantly higher effect estimates among those with lower educational attainment and for Hispanics. For example, while essentially no association was observed for individuals who graduated high school, an interquartile change in several of the components of PM2.5 was associated with a 3 to 5% increase in daily mortality.

Conclusion: There is evidence that exposure to several of the constituents of PM2.5 are important contributors to cardiovascular mortality. Many of these constituents are generated by motor vehicles, especially those with diesel engines, and by residential wood combustion. In addition, factors associated with low educational attainment appear to significantly increase the susceptibility of the population.

Background: Arsenic is a known carcinogen but no estimate has been made of the risk of lung cancer from the widespread contamination of drinking water in rural areas of Bangladesh.

Objectives: To determine whether estimated exposure to arsenic in drinking water used by villagers in Bangladesh differed between cases of lung cancer and those found to have non-malignant lesions

Methods: Data were obtained from 7286 subjects with lung biopsy 2003-2006 at a single diagnostic centre that took referrals from throughout Bangladesh. Analysis was limited to 5372 living in villages for the last 10 years who reported using tube well water. Of these, 3223 with a primary lung tumour were cases and 1588 with non-malignant lesions referents in an unmatched analysis. Arsenic exposure was estimated by average concentrations for each of 64 districts. Logistic regression was used to test the effects of age, arsenic and smoking on risk and to investigate relation to cell type.

Results: Male cases were older than referents and more likely to smoke, to smoke more than 20 units/day and to smoke bidi. Odds ratios for lung cancer increased steadily with mean arsenic concentration but the confidence interval excluded 1.0 only at concentrations >100 µg/L (OR=1.45, 95%CI 1.16-1.80). This trend was seen only in smokers where the increased risk at >100 µg/L was 1.65 (95%CI 1.25-2.18). A similar trend was seen in women smokers. Squamous cell type was more frequent in smokers and, having adjusted for smoking, in districts with arsenic concentrations above100 µg/L

Conclusions: Among Bangladeshis who smoke, those whose drinking water is contaminated with arsenic at concentrations > 100 µg/L are at increased risk of lung cancer. With high levels of exposure misclassification and short latency of exposure, the study cannot estimate or exclude likely long term risk in non-smokers and at lower arsenic concentrations.

Objectives: To investigate whether common important health conditions and their treatments increase risks of occupational injury.

Methods: A systematic search was conducted of Medline, Embase and PsycINFO databases from inception to November 2006 employing terms for occupational injury, medications, and a broad range of diseases and impairments. Papers related solely to driving, alcohol, or substance abuse were excluded, as were studies that did not allow analysis of injury risk. For each paper that was retrieved we abstracted standard information on the population, design, exposure(s), outcome(s), response rates, confounders and effect estimates; and rated the quality of information provided.

Results: We found 38 relevant papers (33 study populations): 16 studies were of cross-sectional design, 13 were case-control and four were prospective. The overall quality was rated as excellent for only two studies. Most commonly investigated were problems of hearing (15 studies), mental health (11 studies) and vision (10 studies).

For impaired hearing, neurotic illness, diabetes, epilepsy and use of sedating medication there were moderate positive associations with occupational injury (ORs 1.5–2.0), but there were major gaps in the evidence base. Studies on vision did not present risks by category of eye disease; no evidence was found on psychotic illness; for diabetes, epilepsy and cardiovascular disease there were remarkably few papers; studies seldom distinguished risks by sub-category of external cause or anatomical site and nature of injury; and exposures and outcomes were mostly ascertained by self-report at a single time point, with a lack of clarity about exposure timings.

Conclusion: Improved research is needed to define the risks of occupational injury arising from common health complaints and treatments. Such research should delineate exposures and outcomes in more detail, and ensure by design that the former precede the latter.

ABSTRACT Objectives: To examine the efficacy of a participatory ergonomics intervention in preventing musculoskeletal disorders among kitchen workers. Participatory ergonomics is commonly recommended to reduce musculoskeletal disorders, but evidence for its effectiveness is sparse.

Methods: A cluster randomized controlled trial among the 504 workers of 119 kitchens in Finland was conducted during 2002-2005. Kitchens were randomized to an intervention (n = 59) and control (n = 60) group. The duration of the intervention that guided the workers to identify strenuous work tasks and to seek solutions for decreasing physical and mental workload, was 11 to 14 months. In total, 402 ergonomic changes were implemented. The main outcome measures were the occurrence of and trouble caused by musculoskeletal pain in seven anatomical sites, local fatigue after work, and sick leave due to musculoskeletal disorders. Individual level data were collected by questionnaire at baseline and every three months during the intervention and one-year follow-up period. All response rates exceeded 92%.

Results: No systematic differences in any outcome variable were found between the intervention and control groups during the intervention or during the one-year follow-up.

Conclusions:The intervention did not reduce perceived physical work load and no evidence was found for the efficacy of the intervention in preventing musculoskeletal disorders among kitchen workers. It may be that a more comprehensive redesign of work organization and processes is needed, taking more account of workers' physical and mental resources.

Abstract Objectives The association of work stressors and adult psychiatric diagnoses may be biased by prior psychological distress influencing perception of work or selection into unfavourable work. This study examines the extent to which the association between work stressors and adult psychiatric diagnoses is explained by associations with earlier psychological distress and whether childhood and early adulthood psychological distress influence reported midlife work characteristics.

Methods Follow-up at 45 years of 8243 participants in paid employment from the 1958 British Birth Cohort. Karasek's work characteristics and psychiatric diagnoses (revised-Clinical Interview Schedule) were measured at 45 years. Childhood internalising and externalising problems were measured at 7, 11 and 16 and malaise at 23 and 33 years. Results Internalising behaviours in childhood and early adult psychological distress predicted adverse work characteristics in mid-adulthood. High job demands (women Relative risk ratio(RRR) =1.75, 95%CI 1.2-2.5; men RRR=4.99, 95%CI 2.5-10.1), low decision latitude (RRR=1.46, 95%CI 1.1-1.9) high job strain (OR=1.88, 95%CI1.5-2.4), low work social support (RRR=1.97, 95%CI1.5-2.6) and high job insecurity (OR=1.86, 95%CI 1.4-2.4) were associated with mid-adulthood diagnoses. The association between work stressors and mid-adulthood diagnoses remained after adjustment for internalising behaviours and malaise at 23 and 33 years although diminished slightly in magnitude (eg adjusted RRR for support =1.82, 95%CI1.4-2.4; job strain OR=1.78, 95%CI 1.4-2.3).

Conclusions Childhood and early adulthood psychological distress predict work characteristics in mid-adulthood but do not explain the associations of work characteristics with depressive episode and generalized anxiety disorder in midlife. Work stressors are an important source of preventable psychiatric diagnoses in midlife. Psychological distress may influence selection into less advantaged occupations with poorer working conditions that may increase the risk of future depressive and anxiety disorders.

ObjectivesTo alleviate traffic congestion in Central London, the Mayor introduced the Congestion Charging Scheme (CCS) in February 2003. To date, the impacts of the CCS on levels of traffic-related air pollution and associated health outcomes have not been assessed. We modelled the impact of the CCS on levels of traffic-pollutants, life expectancy, and socioeconomic inequalities.

Methods Annual average NO2 and PM10 were modelled using an emission-dispersion model. We assumed the meteorology and vehicle fleet remained constant during the pre and post-CCS periods to isolate changes due to traffic flow. Air pollution concentrations were linked to small area socioeconomic, population, and mortality data. Associated changes in life expectancy were predicted using life-table analysis and exposure-response coefficients from the literature.

Results Before the introduction of the CCS, annual average NO2 was 39.9µg/m3 and PM10 was 26.2µg/m3 across Greater London. Concentrations were 54.7µg/m3 for NO2 and 30.3 µg/m3 for PM10 among census wards within or adjacent to the charging zone. Absolute and relative reductions in concentrations following the introduction of the CCS were greater among charging zone wards compared to remaining wards. Predicted benefits in the charging zone wards were 183 years of life per 100,000 population compared to 18 years among the remaining wards. In London overall, 1,888 years of life were gained. More deprived areas had higher air pollution concentrations; these areas also experienced greater air pollution reductions and mortality benefits compared to the least deprived areas.

Conclusions The CCS, a localized scheme targeting traffic congestion, appears to have modest benefit on air pollution levels and associated life expectancy. Greater reductions in air pollution in more deprived areas are likely to make a small contribution to reducing socioeconomic inequalities in air pollution impacts.

Objectives: Work-related cancers are largely preventable. The overall aim of this project is to estimate the current burden of cancer in Great Britain attributable to occupational factors and identify carcinogenic agents, industries and occupations for targeting risk prevention.

Methods: Attributable fractions and numbers were estimated for mortality and incidence for bladder, lung, non-melanoma skin, and sinonasal cancers, leukaemia and mesothelioma for agents and occupations classified as IARC group 1 and 2A carcinogens with "strong" or "suggestive" evidence for carcinogenicity at the specific cancer site in humans. Risk estimates were obtained from published literature and national data sources used for estimating proportions exposed.

Results: In 2004, 78237 men and 71666 women died from cancer in Great Britain. Of these, 7317 (4.9%) deaths (men: 6259 (8%); women: 1058 (1.5%)) were estimated to be attributable to work-related carcinogens for the 6 cancers assessed. Incidence estimates were 13338 (4.0%) registrations (men: 11284 (6.7%); women 2054 (1.2%)). Asbestos contributed over half the occupational attributable deaths, followed by silica, diesel engine exhaust, radon, work as a painter, mineral oils in metal workers and in the printing industry, environmental tobacco smoke (non-smokers), work as a welder and dioxins. Occupational exposure to solar radiation, mineral oils and coal tars/pitches contributed 2557, 1867 and 550 skin cancer registrations respectively. Industries/occupations with large numbers of deaths and/or registrations include construction, metal working, personal and household services, mining (not metals), land transport and services allied to transport, roofing, road repair/construction, printing, farming, the Armed Forces, some other service industry sectors and manufacture of transport equipment, fabricated metal products, machinery, non-ferrous metals and metal products, and chemicals.

Conclusions: Estimates for all but leukaemia are greater than those currently used in UK health and safety strategy planning and contrast with small numbers (200-240 annually) from occupational accidents. Sources of uncertainty in the estimates arise principally from approximate data and methodological issues. On balance, the estimates are likely to be a conservative estimate of the true risk. Long latency means that past high exposures will continue to give substantial numbers in the near future. Although levels of many exposures have reduced, recent measurements of others, such as wood dust and respirable quartz, show continuing high levels.

Objective: Analysis of a dose-response pattern between exposure to whole body vibration (WBV) and low back pain (LBP) in a group of drivers.

Methods: We assessed individual factors, work-related risk factors, various LBP outcome measures (12-month LBP, driving-related LBP, LBP intensity [Von Korff pain scale¡Y 5] and LBP disability [Roland Morris disability scale ¡Y 12]) in a group of drivers (n=571) approached at baseline (T0), as well as the WBV magnitude of a representative sample of their vehicles (n=49), at two points in time: T0 and one-year follow-up (T1). Data were collected using a self-administered questionnaire and actual field measurements according to the ISO 2631-1. The magnitude and duration of vibration exposure and a variety of daily and cumulative WBV-exposure measures were calculated for each driver.

Results: A sample of 229 drivers (40.1%) completed both questionnaires (T0 and T1). The magnitude of WBV was comparable over time. Depending on the LBP outcome, various individual factors (marital status, back trauma and smoking) and work-related risk factors (previous job with heavy physical loading, lifting, bending and the physical risk index) related significantly to onset (all, p< 0.05). After adjusting for these contributing factors, we found a significant trend (an increase in odds ratios of developing LBP with an increase in WBV exposure) for driving-related LBP with daily driving time (p<0.03), and the cumulative measures total hours of exposure (p<0.01), rooth sum of squares at total dose (p<0.05) and root sum of quads at total dose (p<0.01). No significant trend was found for 12-month LBP. No analysis on a possible dose-response pattern could be derived for either LBP intensity or LBP disability, due to low prevalence.

Conclusion: We found a dose-response pattern between WBV exposure and driving-related LBP. No indication of a dose-response pattern was found between WBV exposure and 12-month LBP. Although this dose-response pattern is only an indication, these findings imply that WBV exposure might contribute to the onset of driving-related LBP.

Objective: To evaluate the association of different indices of traffic-related air pollution (self-report of traffic intensity, distance from busy roads from geographical information system (GIS), area-based emissions of particulate matter (PM), and estimated concentrations of nitrogen dioxide (NO2) from a land-use regression model) with respiratory health in adults.

Methods: A sample of 9,488 25-59 year-old Rome residents completed a self-administered questionnaire on respiratory health and various risk factors, including education, occupation, housing conditions, smoking, and traffic intensity in their area of residence. We used GIS to calculate the distance between their home address and the closest high-traffic road. For each subject, PM emissions in the area of residence as well as estimated nitrogen dioxide (NO2) concentrations as assessed by a land-use regression model (R2 value=0.69) were available. We used generalised estimating equations (GEE) to analyse the association between air pollution measures and prevalence of "ever" chronic bronchitis, asthma, and rhinitis taking into account the effects of age, gender, education, smoking habits, socioeconomic position, and the correlation of variables for members of the same family.

Results 397 subjects (4% of the study population) reported chronic bronchitis, 472 (5%) asthma, and 1227 (13%) rhinitis. Fifteen percent of subjects reported living in high traffic areas, 11% lived within 50m of a high traffic road, and 28% in areas with estimated NO2 greater than 50 µg/m3. Prevalence of asthma was associated only with self-reported traffic intensity whereas no association was found for the other more objective indices. Rhinitis, on the other hand, was strongly associated with all traffic-related indicators (e.g. OR=1.13, 95%CI:1.04-1.22 for 10 µg/m3 NO2), especially among non-smokers.

Conclusions: Indices of exposure to traffic-related air pollution are consistently associated with an increased risk of rhinitis in adults, especially among non-smokers. The results for asthma are weak, possibly due to ascertainment problems.

Objectives. Most previous studies of job strain and cardiovascular risk have been limited to adult data. It remains unclear whether this association might be explained by factors present already before entering work life. We examined whether preemployment family factors and participants’ own dispositional factors contribute to the relationship between job strain and carotid intima-media thickness (CIMT) among male employees.

Methods. The sample was 494 men from the Cardiovascular Risk in Young Finns Study. Parental socioeconomic position and parental life dissatisfaction were assessed at age 9 to 21 years and components of type A behavior (Hunter-Wolf) were assessed at age 12 to 24 before the participants had entered labor market. Job strain, education and CIMT were assessed at age 27 to 39 years when all the participants were employed.

Results. There was an association between higher job strain and increased CIMT in adulthood 0.59 mm [95% CI 0.42-0.76] which was only little affected on adjustment for parental socioeconomic position and parental life dissatisfaction as well as participants' education. However, the job strain/CIMT relationship attenuated 17% to non-significant after taking into account the effect of participants’ type A behavior components.

Conclusions. In this contemporary cohort of men, lack of leadership (a type A behavior component) contributed to the association between job strain and carotid intima-media thickness 15 years later whereas preemployment family factors had only a modest effect on this association.

Background: Wood dust (WD) has been designated as a human carcinogen that can cause sino-nasal cancers. However, evidence on its association with other upper aero digestive tract and respiratory (UADR) cancers is inconsistent.

Objective: To examine the relationship between WD exposure and the risk of different histological sub-types of UADR cancers.

Methods: In a hospital based case-control study conducted at Roswell Park Cancer Institute, Buffalo, NY, USA; we examined the effect of self reported WD exposure on 1522 male UADR cancer cases (241 oral and oropharyngeal, 90 nasal cavity, nasopharyngeal and hypopharyngeal, 124 laryngeal, 809 lung and tracheal and 258 cancers of esophagus and gastric cardia) and 1522 male controls; frequency matched on age and smoking history. Odds ratios (OR) were calculated after adjusting for relevant risk factors including tobacco smoking.

Results: The results show that regular WD exposure was associated with a statistically significant increased risk of 32% for all UADR cancers [Adjusted OR =1.32 (95%CI = 1.01–1.77); p-trend =0.05] and 69% for lung cancer alone [Adjusted OR =1.69 (1.20–2.36); p-trend =0.007]. WD was associated with 82-93% increased risk of squamous cell, small cell and adenocarcinoma of lung and more than twice the risk of developing squamous cell carcinoma of nasal cavity, nasopharynx and hypopharynx; with a significant dose-response relationship. Oral and oropharyngeal cancers showed a non-significant increase in risk. Significant increase in risk of laryngeal and lung cancers was noted for subjects who were regularly exposed to WD for more than 20 years. Cancers of esophagus and gastric cardia did not show any risk associated with WD. WD was associated with a significantly greater risk of UADR cancers among people who have ever smoked than never smokers.

Conclusion: WD exposure is a potential risk factor for UADR cancers, especially for cancers of nasal cavity, nasopharynx, larynx and lung.

Objectives: Although associations have been found between levels of ambient airborne particles and cardiovascular disease (CVD) in the general population, little is known about possible cardiovascular effects from high exposure to particles prevailing in underground railway systems. This led us to investigate risk markers for CVD in employees exposed to particles in the Stockholm underground system.

Methods: Seventy-nine workers in the Stockholm underground were investigated between November 2004 and March 2005. All were non-smokers in the age range 25–50; 54 were men and 25 were women. Three exposure groups were delineated: 29 platform workers with high exposure to particles, 29 train drivers with medium exposure, and 21 ticket sellers with low exposure (control group). A baseline blood sample was taken after two days of vacation, and a second sample after two working days, for analysis of levels of plasminogen activator inhibitor-1 (PAI-1), high-sensitivity C-reactive protein (hs-CRP), interleukin-6 (IL-6), fibrinogen, von Willebrand factor and factor VII. We investigated changes in plasma concentrations between sample 1 and sample 2, and differences in average concentrations between the groups.

Results: No changes between sample 1 and 2 were found that could be attributed to the particle exposure. However, the highly exposed platform workers were found to have higher plasma concentrations of PAI-1 and hs-CRP than the ticket sellers and train drivers. This suggests that there could be a long-term inflammatory effect of the particle exposure. These differences remained for PAI-1 in the comparison between platform workers and ticket sellers after adjusting for body mass index (BMI).

Conclusions: Employees who were highly exposed to airborne particles in the Stockholm underground tended to have elevated levels of risk markers of CVD relative to employees with low exposure. However, the differences observed cannot be linked to the particle exposure as such with certainty.

Objective: To investigate the hypothesized association between risk of hypertension and exposure to high levels of noise using quantitative exposure assessment and administrative health data.

Methods: We followed a cohort of 10,872 sawmill workers in British Columbia from 1991 to 1998. Subjects were linked with Provincial hospital discharge, outpatient and vital status databases. Cases were males who died, had at least one admission to hospital, or who had three doctor visits within 70 days, for hypertension (ICD9 code 401-405). We used two metric types: cumulative exposure, and duration of exposure above thresholds of 85, 90, and 95dBA. Relative risks were estimated using Poisson regression with low-exposure group as controls and adjusting for age, ethnicity, and calendar period.

Results: 828 cases were identified. The results showed a monotonic increase in hypertension incidence with cumulative exposure, and the risk in the highest exposed population was 32% higher than baseline. Similar results were found using duration of exposure metrics. The highest relative risk was 1.5 in workers exposed for more than 30 years at 85 dBA. Trends were statistically significant.

Conclusions: The risk of hypertension was positively associated with noise exposure above 85 dB.

Objectives: We have reported a statistically significant association between alcohol use and deployment to the 2003 Iraq War. This paper assesses the occupational factors and deployment experiences associated with "heavy drinking" in regular UK Servicemen deployed to Iraq in the first phase of the 2003 Iraq War (Operation TELIC 1; the military codename for the conflict in Iraq).

Methods: A random representative sample of 3,578 regular male UK Armed Forces personnel who were deployed to Iraq during Operation TELIC 1 participated in a cross-sectional postal questionnaire study (response rate 61%). Participants completed a questionnaire, between June 2004 and March 2006 (i.e. post-deployment), about their health, including a measure of alcohol use (Alcohol Use Disorders Identification Test - AUDIT), and questions about their experiences on deployment to Iraq. "Heavy drinkers" were identified as those scoring 16 or above on the AUDIT.

Results: After adjustment for socio-demographic and military factors, and the presence of psychological distress, "heavy drinkers" were more likely to have had major problems at home during (odds ratio (OR) 1.33, 95% confidence interval (CI) 1.04-1.70) and following their deployment (OR 1.68, 95% CI 1.32-2.14). Being deployed with their parent unit (OR 1.28, 95% CI 1.02-1.61), medium to high in-theatre unit comradeship (medium: OR 1.35, 95% CI 1.04-1.77; high: OR 1.35; 95% CI 1.02-1.79), and poor unit leadership (OR 1.78, 95% CI 1.37-2.31), were also associated with heavy drinking.

Conclusions: Deployment experiences and problems at home during and following deployment, as well as the occupational milieu of the unit, influence personnel’s risk of heavy drinking.

Background: Evidence from toxicologic studies indicates that the risk of respiratory diseases varies with asbestos fiber length and width. However, there is a total lack of epidemiologic evidence concerning this question.

Methods: Data were obtained from a cohort mortality study of 3072 workers from an asbestos textile plant which was recently updated for vital status through 2001. A previously developed job exposure matrix based on phase contrast microscopy (PCM) was modified to provide fiber size-specific exposure estimates using data from a reanalysis of samples by transmission electron microscopy (TEM). Cox proportional hazards models were fit using alternative exposure metrics for single and multiple combinations of fiber length and diameter.

Results: TEM-based cumulative exposure estimates were found to provide stronger predictions of asbestosis and lung cancer mortality than PCM-based estimates. Cumulative exposures based on individual fiber size-specific categories were all found to be highly statistically significant predictors of lung cancer and asbestosis. Both lung cancer and asbestosis were most strongly associated with exposure to thin fibers (< 0.25 ìm). Longer (> 10 ìm) fibers were found to be the strongest predictors of lung cancer, but an inconsistent pattern with fiber length was observed for asbestosis. Cumulative exposures were highly correlated across all fiber sizes categories in this cohort (0.28-0.99, p-values < 0.0001), which complicates the interpretation of the study findings.

Conclusions: Asbestos fiber dimension appears to be an important determinant of respiratory disease risk. Current PCM-based methods may underestimate asbestos exposures to the thinnest fibers, which were the strongest predictor of lung cancer or asbestosis mortality in this study. Additional studies are needed of other asbestos cohorts to further elucidate the role of fiber dimension and type.

Objectives: This paper presents the risk of death from lung cancer and from other causes of death for the French cohort of uranium miners through 1999 and estimates associations with radon exposure.

Methods: The cohort includes men employed as uranium miners for at least one year between 1946 and 1990. For each miner, vital status and cause of death were obtained from the national registry, and radon exposure was reconstructed for each year. Standardised mortality ratios were computed with national mortality rates as references. Exposure-risk relations were estimated by Poisson regression, with a linear excess relative risk (ERR) model and a 5-year lag.

Results: The cohort included 5086 miners and 153 063 person-years of exposure. The mean duration of follow-up was 30.1 years. In all 4140 miners exposed to radon, the average cumulative exposure was 36.6 WLM. There were 1411 deaths of miners younger than 85 years. The miners did not differ significantly in overall mortality from the general male population. The analysis confirmed an excess risk of lung cancer death (n=159; SMR=1.43; 95%CI=1.22 to 1.68), which increased significantly with cumulative radon exposure (ERR per 100 WLM=0.71; 95%CI: 0.29 to 1.35). The ERR per unit exposure was much higher after 1955, when the accuracy of exposure measurement improved substantially (ERR per 100 WLM=2.00; 95%CI: 0.91 to 3.65). A significant excess of kidney cancer deaths was observed (n=20; SMR=2.0; 95%CI: 1.22 to 3.09), which was not associated with cumulative radon exposure. No excess was observed for other causes of death, except silicosis (n=23; SMR=7.12; 95%CI: 4.51 to 10.69).

Conclusions: The analysis confirmed the excess risk of death from lung cancer associated with low radon exposure. An excess risk of death from kidney cancer was also observed, apparently not associated with cumulative radon exposure.

Objectives: Many occupational exposures causing disease cannot feasibly be eliminated entirely, but policies that reduce the exposures may be under consideration. This paper sets out to clarify how to estimate the reduction in occupational disease following a reduction in exposure, and show a real-data illustration of doing this.

Methods. Modest extensions of standard expressions for attributable fractions permit estimation of fractions by which cases would be reduced by policies that do not eliminate exposure but change exposure distributions. However, this requires information on the exposure-response relationship and on distribution of exposures

Results. From hypothetical scenarios and a real example we explored how attributable cases were distributed by exposure level, and in particular the proportion by which attributable cancers are reduced by eliminating exposures above a limit (the classic occupational limit regulation). We show how this depends on the shape of the exposure-response relationship and to some extent the shape of the exposure distribution, as well as on the proportion exposed above the limit. For linear no-threshold relationships and left-skewed exposure distributions, the majority of the burden may be in a large number of persons experiencing small relative risks, and thus may not be tackled by a strategy to reduce exposures above a certain limit..

Conclusion: With appropriate data, estimating the disease burden in terms of the distribution of exposure is straightforward and can help to clarify the likely outcome of an intervention.

Objectives: We conducted a cross-sectional study to evaluate the occupational risk for Helicobacter pylori infection, on top of other risk factors, in staff members of institutions for people with intellectual disability. In these institutions, the residents had a documented high prevalence of H. pylori infection (86% presenting antibodies). As a control group, we used administrative workers from other companies.

Methods: All participants completed a questionnaire concerning sociodemographic characteristics, medical history and employment data and they underwent a serology test.

Results: 671 staff members of the institutions, and 439 subjects in the control group participated in the study. Prevalence of H. pylori antibodies was significantly higher in the study group than in the control group (40.6% vs. 29.2%; p<0.001). Crude odds ratio for occupational risk was 1.68; adjusting for the confounding effect of age, gender, BMI, smoking, tropical journeys and number of household members during childhood resulted in an even higher (adjusted) OR of 1.98 (95% CI 1.42-2.69). In multiple logistic regression analysis adjusting for variables shown to be confounders, faecal contact continued to be significantly associated with H. pylori infection. Attributable risk was 49.5 %.

Conclusions: H. pylori infection is an occupational risk in healthcare workers working in institutions for people with intellectual disability. We identified faecal contact as an independent occupational risk factor for H. pylori infection.

Objectives: To evaluate exposure estimation methods such as spatially resolved land-use regression models and ambient monitoring data in the context of epidemiologic studies of the impact of air pollution on pregnancy outcomes. Methods: We measured personal 48-hour exposures (NO, NO2, PM2.5 mass and absorbance) and mobility (time activity and GPS) for 62 pregnant women during 2005-06 in Vancouver, Canada, 1-3 times during pregnancy. Measurements were compared to modelled (using land-use regression and interpolation of ambient monitors) outdoor concentrations at subjects’ home and work locations. Results: Personal NO and absorbance (ABS) measurements were moderately correlated (NO: r=0.54, ABS: r=0.29) with monitor interpolations and explained primarily within-subject (temporal) variability. Land-use regression estimates including work location improved correlations for NO over those based on home postal code (for NO: r=0.49 changed to NO: r=0.55) and explained more between-subject variance (4% to 20%); limiting to a subset of samples (N=61) when subjects spent >65% time at home also improved correlations (NO: r=0.72). Limitations of the GPS equipment precluded assessment of including complete GPS-based mobility information. Conclusions: We found moderate agreement between short-term personal measurements and estimates of ambient air pollution at home based on interpolation of ambient monitors and land-use regression. These results support the use of land-use regression models in epidemiologic studies, as the ability of such models to characterize high resolution spatial variability is "reflected" in personal exposure measurements, especially when mobility is characterized.

Objectives: To develop a method for estimating fiber size-specific exposures to airborne asbestos dust for use in epidemiologic investigations of exposure-response relations. Methods: Archived membrane filter samples collected at a Charleston, SC asbestos textile plant during 1964-1968 were analyzed by transmission electron microscopy (TEM) to determine the bivariate diameter/length distribution of airborne fibers by plant operation. The protocol used for these analyses was based on the direct transfer method published by the International Standards Organization (ISO), modified to enhance fiber size determinations, especially for long fibers. Procedures to adjust standard PCM fiber concentration measures using the TEM data in a job-exposure matrix (JEM) were developed in order to estimate fiber size-specific exposures. Results: A total of 84 airborne dust samples were used to measure diameter and length for over 18,000 fibers or fiber bundles. Consistent with prior studies, a small proportion of airborne fibers were longer than >5 µm in length, but the proportion varied considerably by plant operation (range 6.9% to 20.8%). The bivariate diameter/length distribution of airborne fibers was expressed as the proportion of fibers in 20 size-specific cells and this distribution demonstrated a relatively high degree of variability by plant operation. PCM adjustment factors also varied substantially across plant operations. Conclusions: These data provide new information concerning the airborne fiber characteristics for a textile operation used for previous exposure-response analyses. The TEM data demonstrate that the vast majority of airborne fibers inhaled by these workers were shorter than 5 µm in length, and not included in current PCM fiber counts. A new fiber size-specific JEM was developed for use in fiber size-specific risk assessments.

Objectives: NO2 is a major urban air pollutant. Previously reported associations between ambient NO2 and children¡¦s respiratory health have been inconsistent, and independent effects of correlated pollutants hard to assess. We examine effects of NO2 on a spectrum of 11 respiratory symptoms, controlling for PM10 and SO2, using a large pooled dataset.

Methods: Cross-sectional studies were conducted in Russia, Austria, Italy, Switzerland and The Netherlands, during 1993-1999, contributing in total 23,955 children. Study-specific odds ratios for associations with ambient NO2 are estimated using logistic regressions with area-level random effects. Heterogeneity between study-specific results, and mean estimates (allowing for heterogeneity) are calculated.

Results: Long-term average NO2 concentrations were unrelated to prevalences of bronchitis or asthma. Associations were found for sensitivity to inhaled allergens and allergy to pets, with mean odds ratios around 1.14 per 10 ìg/m3 NO2. SO2 had little confounding effect, but an initial association between NO2 and morning cough was reduced after controlling for PM10. Associations with reported allergy were not reduced by adjustment for the other pollutants. Odds ratios for allergic symptoms tended to be higher for the 9-12 year old children compared to the 6-8 year old children.

Conclusions: Evidence for associations between NO2 and respiratory symptoms was robust only for inhalation allergies. NO2 most likely is acting as an indicator of traffic-related air pollutants, though its direct effect cannot be ruled out. This remains important, as policies to reduce traffic-related air pollution will not result in rapid reductions.