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Characterisation Method Information
Characterisation Method Name:
PAC impact on YOLL
Date Completed:
Principal Method Name:
EPS: cancer pathway
Method Description:
YOLL stands for Year of Lost Life.


The characterisation factor is determined by the empirical method.

Category indicator value in system considered

The average Swedish population exposure to PAC was estimated to 19 ng/m 3 (Boström et al 1994). Törnqvist and Ehrenberg (1990) estimate the number of cancer incidences from PAC to about 300. Only a fifth originates from direct exposure. The most important pathway is deposition to vegetation and uptake via the food chain.
If the PAH (PolyAromatic Hydrocarbons) concentration is assumed to be proportional to the soot or black smoke
concentration measured in urban locations, the global cancer rates may be estimated from
the black smoke results obtained in the UN/GEMS monitoring network. The average,
annual black smoke concentration in the cities participating in this network was in the order of 80 microgram per cubic meter 1980-84. In Sweden it is around 10. However, the GEMS network concentrates on large cities where the WHO air quality guidelines may be exceeded. To estimate the ratio between Swedish and global smoke concentrations the ratio between the Copenhagen and global averages in the GEMS network is used. This ratio is a factor of five. As a large part of the population outside OECD (Organisation for Economic Co-operation and Development) live in the countryside (about 50%) this ratio is probably lower for the entire global population. A factor of three seems reasonable. The total number of cases in the world would therefore be 300*5300/8.6*3=554651.

The mortality for all sorts of cancer in the European union was 62 % 1990. (Berrino
1999). The global average 1990 may be calculated to 64% using statistics from IARC (International Association for Research on Cancer)(Parkin et al., 1990, Pisani et al., 1990). The average reduction of life expectancy was estimated in "Benzene impact on YOLL" to 24 years. Thus, the category indicator value is 554651*0.64*24= 8.52E+06 YOLL.

Contribution to category indicators value from a flow unit

The global emission of PAH is estimated through its normal ratio to NOx in Swedish
urban air. This ratio is used as car exhausts probably is the main source to the population dose, with small-scale wood firing as the second most important and because there is no significant sink processes that would be able to change the PAH/NOx ratio in the urban air. The ratio was determined in Gothenburg (Steen, B. IVL report B 1033, 1991) to be 0.2E-03 . The global anthropogenic emission of NOx is 75 tg/year. Thus the global PAH (PolyAromatic Hydrocarbons) emission would be 0.2E-03 *75E+12 g = 1.5E+10 g or 1.50E+07 kg. The contribution is thus 1/1.5E+07 = 6.67E-08 kg -1 .

Calculation of characterisation factor

The characterisation factor is 8.52E+06 *6.67E-08 = 0.568 YOLL/kg PAC.

Literature Reference:
1. 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. 2. Törnqvist, M. and Ehrenberg, L. “Genotoxiska effekter av allmänna luftföroreningar i tätort”. In “Stadsluften”ed. Möller, L., Swedish Environment Protection Board, 1990 3. 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 4. Steen, B., (1991) “Sveriges befolknings exponering för kväveoxider och mutagena ämnen i luft (Exposure of the Swedish Population to Nitrogen Oxides and mutagens in air)”, Swedish Environmental Research Institute, Report B 1033, September 1991. (In Swedish)
Methodological Range:
The system is global and the year is 1990. Most of the exposure occurs in urban areas why the characterisation modelling is focused on urban areas.
PAC PolyAromatic Compounds.

Existing Characterisation Factors of PAC impact on YOLL
Characterisation Parameter Category Indicator Impact Indication Principle Aspect Substance Quantity Unit Notes
CFactor YOLL EPS/2000
Type = Emission
Direction = Output
Media = Air
Geography = *
PAC 0.568 p yr/kg cancer pathway