Concentrations of polychlorinated naphthalenes in food and human dietary exposure: A review of the scientific literature

In general, for most environmental persistent organic pollutants (POPs), dietary intake is the main way of exposure. Polychlorinated naphthalenes (PCNs) are a family of two-ringed aromatic compounds, which are ubiquitous environmental contaminants, being structurally similar to PCDD/Fs and PCBs. Although the production and use of PCNs were banned in the USA and Europe some decades ago, due to their persistent properties, PCNs remain still present in the environment, being able to enter the food chain. The present paper was aimed at reviewing the results of the studies focused on determining the levels of PCNs in foods. The human dietary intake of these compounds was also reviewed with the few available data. The information on the levels of PCNs in foodstuffs is currently more abundant than that found in a previous review (Domingo, 2004). Since then, China is the country that has contributed with the greatest number of studies. The results of most surveys seem to suggest that human health risks of PCNs due to dietary exposure should not be worrying. However, because of the important differences in the methodology of the published studies, the comparison of the results is not easy, although there seems to be a general trend towards a decrease in the levels of PCNs in foods. In the next few years, a continued reduction of the environmental levels of PCNs is still expected. Therefore, a direct repercussion of the concentrations of these pollutants in foodstuffs must be also noted. Consequently, a reduction of the dietary exposure to PCNs should be expected. Anyway, to establish the tolerable dietary intake of PCNs is a key issue for assessing human health risks of these pollutants.