|Characterisation Method Name:|
|Cd air emissions impact on YOLL|
|Principal Method Name:|
|EPS: inhalation pathway|
|YOLL stands for Year of Lost Life.|
Model for direct inhalation pathway
The characterisation factor is determined by the empirical method.
Category indicator value in system considered
USEPA estimates the lifetime risk for cancer to be 1.8E-03 /mg/m 3 of Cd in air (1999).
The mortality for all sorts of cancer in the European union was 62 % 1990. (Berrino et.al.
1999). The global average 1990 may be calculated to 64% using statistics from IARC.
(Parkin et al., 1990, Pisani et al.,1990). The average reduction of life expectancy was
estimated in "Benzene impact on YOLL" to 24 years. The Swedish average life expectancy is 78 years. The mean population exposure is about 0.2 ng/m3 in Sweden (Boström, 1994). This will give 0.62*1.8E-03 *2E-04 *8.6E+06 /78*24 = 0.59 YOLL among the 8.6 million inhabitants.
Contribution to category indicators value from a flow unit
The total emission of Cd in Sweden was around 5000 kg 1985 (Swedish EPA, 1992). The
contribution from background levels is not negligible and it has to be decided on which
emission that shall be allocated to the indicator value 0.61 YOLL. The contribution to human exposure concentrations from the regional background was estimated to about
50% in rural Belgium (Fergusson, 1990). In Olso the regional background was measured
by Sivertsen and Vitols (1981). They found concentrations about 0.4 ng/m 3 , about the
same background levels as in Belgium. It seems reasonble to assume that the
contributions in Sweden are about the same, i. e. 50%. However some of the 5000 kg’s
are contributing to human exposure outside Sweden. Considering the prevailing south-westerly winds, the trade balance ought to negative in terms of human exposure to
ambient air concentrations. We therefore allocate more than 5000 kg but less than 1.5
times the 5000 kg. As a rough estimate 1,25*5000= 6250 kg is allocated to the indicator value. Thus the contribution to the annual category indicator value is therefore 1/6250
Calculation of characterisation factor
A characterisation factor for Sweden would thus be 0,59/6250 = 9.44E-05 YOLL per kg of Cd emitted to air. The system border was actually 20 years and therefore the emission and effect should be summarised over 20 years before the calculation of the
characterisation factor was made. However as the effect is linearly dependent of the
emission the characterisation factor would still be 9.44E-05 YOLL/kg Cd.
|1. USEPA, IRIS database (1999). 2. Berrino, F., Capocaccia, R., Esteve, J., Gatta, G., Micheli, A., Sant, M., & Verdecchia, A. (1999) Survival of Cancer Patients in Europe in the late eighties: The EUROCARE II Study (IARC Scientific Publication No. 151) International Agency for Research on Cancer, Lyon. In press 3. Boström, C-E., Almén, J., Steen, B. and Westerholm, R., “Human Exposure to Air Pollution” Environmental Health Perspectives, Vol 102, Suppplement 4, October 1994, p.39-47. 4. Parkin, D.M., Pisani, P. and Ferlay, J., “Estimates of the worldwide mortality from 25 major cancers in 1990”. International Journal of Cancer. (In Press)|
|In terms of contribution to population exposure urban populations are receiving the highest doses. The main contribution comes from sources in the urban area, but in Southern Sweden the regional background is also important. This means that the trans-boundary pollution can not be neglected (Sievertsen 1986) and that both to Swedish and external sources must be allocated to the category indicator value. Considering an incubation time of the order of 20 years, and that most of the data available are from 1985 the system is defined as Sweden at the state of 1985 during 20 years.|
|Characterisation Parameter||Category Indicator||Impact Indication Principle||Aspect||Substance||Quantity||Unit||Notes|
|As||9.44E-05||p yr/kg||inhalation pathway|