… Number concentrations of two fractions of ultra fine particles. Annual geometric mean and
standard deviation of data from winter 1991/92 to winter 2000/01 at Erfurt/Germany. The dotted …

… particle-control activities. Not only are the remaining scientific questions significant, but the
particle exposure/health effects … relating to the nature of effects of population exposures to low …

… particle composition is believed to affect health risks from PM exposure, our current health-based
air quality standards … (particles 2.5 microm or smaller in aerodynamic diameter), which …

… The current regulatory standards for particulate matter are based largely upon associations
for adverse health effects obtained from epidemiology studies using central area monitors. …

… Even less is known about the respiratory health effects of … We reviewed studies examining
respiratory health effects of UFPs … 18,230 particles/cm 3 (standard deviation = 17,300 particles/…

… standards and the California sulfate standard treat an exposure to each PM sulfate, at the
same AD, concentration, and averaging time, as having exactly the same human health effect. …

… particles are needed. Due to the paucity of human and animal data on the influence of particle
size on observed health effects… possible adverse health effects. It is clear that the toxicity of …

… particle excursions to 24 hr average particle levels, and evaluates the possible public health
… This short time resolution adds power to ongoing UK studies of particle health effects. …

… Adverse health effects of exposure to particles have been … studies performed by the Health
Effects Institute (HEI) … extended the knowledge on health effects of particles. To some extent, …

Background: Specific characteristics of particulate matter (PM) responsible for associations
with respiratory health observed in epidemiological studies are not well established. High …