The German view: effects of nitrogen dioxide on human health--derivation of health-related short-term and long-term values.
The presented overview concerning health relevant effects caused by nitrogen dioxide (NO2) resumes the current state of results from animal experiments and human studies (epidemiology and short-term chambers studies). NO2 concentrations applied in animal experiments were mostly considerably higher than in ambient air. Therefore, short- and long-term limit values were derived from human data. Experimental studies conducted with humans demonstrate effects after short-term exposure to concentrations at or above 400 microg NO2/m3. Effects on patients with light asthma could not be observed after short-term exposure to concentrations below 200 microg/m3. On basis of epidemiological long-term studies a threshold below which no effect on human health is expected could not be specified. Two short-term limit values have been proposed to protect public health: a 1-h value of 100 microg/m3 and a 24-h mean value of 50 microg/m3. Due to the limitations of epidemiological studies to disentangle effects of single pollutants, a long-term limit value cannot be easily derived. However, applying the precautionary principle, it is desirable to adopt an annual mean of 20 microg NO2/m3 as a long-term mean standard to protect public health.
Kraft
Martin
M
Ministry of the Environment and Conservation, Agriculture and Consumer Protection of the state of North Rhine-Westphalia, Düsseldorf, Germany. martin.kraft@munlv.nrw.de
Eikmann
Thomas
T
Kappos
Andreas
A
Künzli
Nino
N
Rapp
Regula
R
Schneider
Klaus
K
Seitz
Heike
H
Voss
Jens-Uwe
JU
Wichmann
H Erich
HE
D000393:Air Pollutants / Q000592:standards* / Q000633:toxicity; D000818:Animals; D004781:Environmental Exposure; D005858:Germany; D006760:Hospitalization; D006801:Humans; D009026:Mortality; D009585:Nitrogen Dioxide / Q000592:standards* / Q000633:toxicity; D019055:No-Observed-Adverse-Effect Level; D012140:Respiratory Tract Diseases / Q000139:chemically induced / Q000517:prevention & control*; D018570:Risk Assessment; D001335:Vehicle Emissions
D000393:Air Pollutants; D001335:Vehicle Emissions; D009585:Nitrogen Dioxide