Environmental Standards and Guidelines

Abstract

This chapter describes the environmental standards for PAHs, especially benzo[a]pyrene (BaP), which are substances that increase the risk of cancer in humans. Although there is no environmental standard in the world, several criteria (such as target values, setting values, and reference levels) have been considered by several organizations and countries. These range from 0.1 to 2.5 ng m⁻³. In the case of the World Health Organization (WHO) air quality guidelines, the reference level (0.12 ng m⁻³) was estimated assuming WHO unit risk for lung cancer PAH mixtures and an acceptable risk of additional lifetime cancer risk of approximately 1 × 10⁻⁵.

Results from a trend analysis of BaP show that the concentrations of BaP have decreased with seasonal variation with highs in the winter and lows in the summer in European Monitoring and Evaluation Programme (EMEP) regions as well as Japan. The reduction of [BaP] in the EMEP region during the period from 1990 to 2012 was 28%. However, [BaP] slightly increased (about 1%) in 2012. The annual reduction rate for each country in the EMEP region was subjected to large variability. In Japan, reductions in [BaP] between 2002 and 2012 was estimated at about 49%.