Observations of volatile organic and sulfur compounds in ambient air and health risk assessment near a paper mill in rural Idaho, U. S. A.

Özet

The Lewis-Clark Valley is a rural area that includes the cities of Lewiston, Idaho and Clarkston, Washington andthe surrounding areas. The largest industry in the Lewis-Clark Valley is a pulp paper mill located in Lewistonwhich emits particulate matter and odorous sulfur air pollutants. This study analyzed the Lewis-Clark Valley aircomposition and seasonal, temporal and spatial variations of volatile organic compounds (VOCs) from 2017 to2018 to determine potential health risks of the paper mill emissions to the surrounding community. Both activeand passive air sampling via sorbent tubes were analyzed by thermal desorption - gas chromatography-massspectrometry (TD-GC-MS). Fifty VOCs including benzene, toluene, chloroform, dimethyl sulfide and dimethyldisulfide were measured in the ambient air of the Lewis-Clark Valley at ten different sites, totaling over 800samples. In addition, passive sorbent tubes were deployed in 2018 to obtain monthly averages in Lewis-ClarkValley and three urban locations in Idaho and Washington for comparison. United States EnvironmentalProtection Agency (2001) methodology was used to assess cancer risks in the community based on the upperconfidence levels of five carcinogens and nine air toxics. The Lewis-Clark Valley had similar levels of benzene tourban areas but had a strong signature of chloroform and sulfides from the paper mill. The cumulative cancerrisk was 2 x 10−6 - 11 × 10−6, mainly due to the compounds chloroform, benzene and carbon tetrachloride. Thehazard index of other air toxics was less than one. Overall, these air pollutants were considered low risk to thelocal population.