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Characterisation Method Information
Characterisation Method Name:
H2S impact on nuisance
Date Completed:
Principal Method Name:
EPS: secondary sulphur dioxide pathway and odour pathway
Method Description:
Model 1, secondary sulphur dioxide pathway

The characterisation factor is determined by an equivalency method using SO2 as a reference.

Equivalency factor

It is assumed that almost all hydrogen sulphide is oxidised to SO2 in the atmosphere. Therefore 1 kg of H2S is equal to 1.49 kg SO2.

Calculation of characterisation factor

The characterisation factor for SO2 was estimated in "SO2 impact on nuisance" to 6.45E-03 person-years per kg SO2. The characterisation factor for H2S is therefore 1.49*(6.45E-03 ) = 9.61E-03 person-years/kg H2S.

Model 2, odour pathway

The characterisation factor is determined by the empirical method. Sweden is used as a
sample of the global system. Having a large portion of industrial H2S sources (pulp mills) it may give an overestimation of the global average characterisation factor as threshold levels more frequently are exceeded. On the other hand is the population density is lower than average, which could give an underestimation of the characterisation factor.

Category indicator value in system considered

Most inhabitants in Sweden have experienced odour from pulp mills. No data on odour frequency for the whole population has been available. However, approximately 10000 person live in areas close to pulp mills where the odour frequency exceeds 1% of the
time. The 1% is the target level in many permits given to the pulp industry. A rough
guess is that the total population exposure in person-years is about twice as high. From
measurements in northern Sweden and by the use of source apportionment techniques it
has been found that H2S is contributing with about half of the odour. Organic sulphides
and therpenes make up for the rest. Therefore, 0.01*10000*2*0.5 = 100 person-years of nuisance is allocated to H2S emissions.

Contribution to category indicators value from a flow unit

The total process sulphur emissions from kraft pulp mills in Sweden was 5400 tons 1993. (Swedish EPA report 4348) A minor part of these is reduced in form of H2S. A rough estimate is 100 tons.

Calculation of characterisation factor

100 person-years divided by 1E+05 kg is 1E-03 person-years of nuisance per kg of H2S.
Literature Reference:
Steen B (1999b): A systematic approach to environmental priority strategies in product development (EPS). Version 2000 Models and data of the default method CPM report Chalmers University of Technology Sweden
Methodological Range:
The system is global and the time period is 1990.

Existing Characterisation Factors of H2S impact on nuisance
Characterisation Parameter Category Indicator Impact Indication Principle Aspect Substance Quantity Unit Notes
CFactor Nuisance EPS/2000
Type = Emission
Direction = Output
Media = Air
Geography = *
H2S 9.61E-03 p yr/kg 2 pathways