TY - JOUR T1 - Work in brief JF - Occupational and Environmental Medicine JO - Occup Environ Med SP - 1 LP - 1 VL - 64 IS - 1 AU - Keith Palmer Y1 - 2007/01/01 UR - http://oem.bmj.com/content/64/1/1.2.abstract N2 - Environmental concentrations of inhaled particulate matter (PM) can vary rapidly; PM can also affect blood and vagal tone within a matter of minutes. However, little is known about the transient risks to health over such short time frames. Yamazaki et al1 examine the relation between hourly time-lagged concentrations of PM in 13 urban areas of Japan and deaths due to stoke, ascertained from the official records. In case-crossover analysis, the 1-h mean concentration of PM7, measured 2 h before death, was associated with deaths due to intracerebral haemorrhage (odds ratio 2.4 for PM7 ⩾200 μg/m3), but not deaths due to ischaemic stroke. An … ER -