Toxic equivalency factors for PAH and their applicability in shellfish pollution monitoring studies©British Crown copyright 2002.

Abstract

Fish and shellfish are exposed to a wide range of polycyclic aromatic hydrocarbons (PAH) following oil spills at sea, and can become contaminated as a result. Finfish have a more effective mixed-function oxidase enzyme system than shellfish, and are therefore able to metabolise and excrete PAH more effectively than the invertebrates. Thus, contamination by high-molecular weight PAH, including those with carcinogenic potential and so of concern with regard to human consumers, is therefore usually observed in shellfish, and particularly in bivalve molluscs. Oil spills are not the sole source of PAH, however, as parent compounds are also generated by a wide range of combustion processes. In this paper, consideration is given to monitoring data gathered following recent oil spills (both of crude oil and diesel fuel), alongside data from other studies. These include studies conducted around a former gasworks site and downstream of an aluminium smelter in the UK, and from mussel monitoring studies undertaken in the UK and the USA (including the Exxon Valdez oil spill and the National Status and Trends programme), and in other countries in Europe. For comparative purposes the PAH concentrations are summed and also expressed as benzo[a]pyrene equivalents, their relative concentrations being weighted in relation to the carcinogenic potential of individual PAH compounds using toxic equivalency factors (TEF). Our aim was to assess the utility of this approach in fishery resource monitoring and control following oil spills. Certainly this approach seems useful from the data assessed in this study. and the relative ranking of the various studies seems to reflect the relative degree of concern for human consumers due to the differing contamination sources. As a simple tool for control purposes it is equally applicable to PAH derived from oil spills, and from industrial and combustion sources.

Influence of fish smoking methods on polycyclic aromatic hydrocarbons content and possible risks to human health

“…The concentration of each of the individual PAH compounds is multiplied by its TEF proposed by (Nisbet and LaGoy, 1992) (Table 1), and these values are summed to yield benzo(a) pyrene equivalent concentrations, TEQBaP (AFSSA, 2003). This technique has been applied successfully to smoked and fresh seafood monitoring studies, and other wider monitoring programmes (Law et al, 2002). The mutagenicity of individual PAHs relative to B(a)P had also been computed using the mutagenic equivalency factor (MEF) proposed by Durant et al (1996Durant et al ( , 1999 as shown in Table 1.…”

Bioethanol–gasoline fuel blends: Exhaust emissions and morphological characterization of particulate from a moped engine

“…TEFs were devised to compare the carcinogenic potency of the individual PAH with the carcinogenicity of benzo[a]pyrene (expressed as BaPeq), which is considered to be one of the most toxic of the PAHs and is often used as an indicator for this group of compounds. To date, only a few proposals for the TEFs for PAHs are available; a good summary of TEFs reported in literature is provided by Law et al (2002). Among them, the list of the TEFs proposed by Nisbet and LaGoy (1992) seems to better reflect the actual state of knowledge on the human health risk associated with inhalatory exposure to PAH mixtures.…”

Polycyclic Aromatic Hydrocarbons in Baltic Sea Bivalves

“…Toxic equivalency factors are used to evaluate contamination (23). In the case of PAHs, the carcinogenic potency of individual PAHs is expressed relative to that of benzo[a]pyrene (BaPE).…”

“…The equivalency values of individual PAHs are summed to yield the total BaPEs. A number of sets of toxicity/potency equivalency factors can be found in the literature, as presented by Law (23), though all are based on a unit value for benzo [a]pyrene because the toxicology data for this compound are much better than the data for other PAHs (23). These various sets of factors differ in the data used in the calculation: Data are selected according to the matrices of interest, so that the factors applied for particular compounds may be different.…”