Table 1

Studies evaluating the association of telomere length with environmental and occupational chemicals

Environmental chemicalsSamplesSample size and mean/median TL (95% CI), p valueMethods and coefficientTL in exposed subjects relative to controls% Change (95% CI), p valueVariables
BC8WBCs165 never-smoking men: median 1.24Q-PCR
8.7%
Short−7.6% (−12.8 to 2.1), p=0.008Neg: age
Pos: statin treatment
Benzene and toluene9WBCs77 traffic officers: 1.10 (1.04 to 1.16)
57 office workers: 1.27 (1.20 to 1.35)
p<0.001
Q-PCRShortBenzene: −6.4% (2.1% to −10.4%), p=0.004
Toluene: −6.2% (1.7% to −10.4%), p=0.008
Neg: age; smoking
PAHs10WBCs48 coke-oven workers: 0.99 (0.31 to 3.00)
44 unexposed controls: 1.20 (0.43 to 2.12)
p=0.038
Q-PCR
10%
ShortWorkers: TL decreased with longer duration of work, p=0.039Neg: years of work, p53 hypomethylation
PAHs11WBCs145 coke-oven workers: 1.10±0.75
68 controls: 1.43±1.06
p=0.026
Q-PCRShortNANeg; age, drinking
N-nitrosamines12WBCs157 rubber workers: median 0.71, range 0.16–1.3Q-PCRShortβ=5.3 (−9.5 to −0.97), p=0.016Neg: age, para-toluidine
Occupational exposures to paints and pesticides13WBCs13 exposed MDS patients: 2.97±1.48
47 non-exposed MDS patients: 4.23±2.44
p=0.09
Q-PCRShortNANA
Occupational exposures to pesticides14WBCs20 exposed MDS patients: MESF<10
13 non-exposed MDS patients: MESF>10
p=0.0013
FISHShortNANA
Lead15WBCs60 battery workers with normal lead level: 1.91±0.46
84 battery workers with abnormal lead level: 1.66±0.63
p=0.01
Q-PCRShortAll workers: −0.70 (−0.79 to −0.56), p<0.0001Neg: BMI, years of working, drinking
Occupational exposure in car mechanical workshops16Buccal cells120 exposed workers: 0 to 4.0
120 unexposed controls: 0 to 53.08
p=0.001
Q-PCRShortNANeg: age, years of working
Waste landfill sites17WBCs50 exposed pregnant women: mean 1.27
50 pregnant women: mean 3.11
p<0.001
Q-PCR
Southern blot
ShortNANeg: hTERT mRNA,
Pos: distance from polluted area
PM7WBCs60 truck drivers: 0.79 (0.67 to 0.93)
60 office workers: 0.87 (0.74 to 1.03)
p=0.002
Q-PCR
8.1%
Long (short exposure)
Short (long exposure)
PM10 in all subjects:
Examination day: 8.0 (1.7 to 14.6), p=0.02
1 day: 9.8 (3.3 to 16.8), p=0.004
1–2 days: 7.8 (−0.2 to 16.3), p=0.06
1–14 days: −13.4 (−24.2 to −1.1), p=0.04
Neg: blood pressure,
gender (men<women)
Arsenic37WBCs161 highly exposed participants
41 low-exposed participants
Median 0.37, range 0.18–0.67 in all subjects
Q-PCRLongβ=0.65×10−4 (0.031×10−4 to 1.3×10−4), p=0.04Neg: age, BMI
Pos: fraction of DMA
POPs38WBCs84 healthy subjects: 2.02±0.32Q-PCRLongΓ=0.23 to 0.31 for OC pesticides
Γ=0.32 to 0.36 for PCB pesticides
Neg: age, BMI, smoking, drinking, blood pressure
Short-term PM39WBCs63 workers:
baseline: 1.23±0.28, post-exposure: 1.43±0.51
p<0.001
Q-PCR
8.1%
LongIn postexposure:
PM10: β=0.30 (0.11 to 0.49), p=0.002
PM1: β=0.29 (0.01 to 0.57), p=0.042
Neg: methylation of hTERT at position 3
  • BC, black carbon; BMI, body mass index; DMA, dimethylarsinic acid; FISH, fluorescence in situ hybridisation; hTERT, human telomerase reverse transcriptase; MDS, myelodysplastic syndromes; MESF, molecular equivalent of soluble fluorescence; NA, not applicable; Neg, negative; OC, organochlorine, PAHs, polycyclic aromatic hydrocarbons; PCB, polychlorinated biphenyls; PM, particular matter; POPs, persistent organic pollutants; Pos, positive; Q-PCR, quantitative PCR; TL, telomere length; WBCs, white blood cells.