Comprehensive Evaluation of Dietary Exposure and Health Risk of Polychlorinated Naphthalenes

Intake
from food is considered an important route of human exposure
to polychlorinated naphthalenes. To our knowledge, several studies
have quantified dietary exposure but only in European countries and
measuring only a few of the 75 congeners. In addition, the influence
of source diversity on human exposure has seldom been assessed. We
analyzed 192 composite food samples composed of 17,280 subsamples
from 24 provinces in China to measure the concentrations of polychlorinated
naphthalenes and estimate their daily intake and potential health
risks on a national scale. The estimated cancer risk was in the range
of 6.8 × 10–8 to 4.6 × 10–7. We compared our findings for 75 congeners with reports in the literature
that quantified only 12 congeners. We estimate that these 12 congeners
contribute only approximately 4% to the total mass daily intake of
polychlorinated naphthalenes and 70% to the total toxic equivalent
quantity, indicating underestimation of dietary exposure. The contributions
of combustion-associated congeners to the total concentrations of
polychlorinated naphthalenes were in the range of 31–52%, suggesting
that the ongoing unintentional release of these compounds from industrial
thermal processes is an important factor in polychlorinated naphthalene
contamination and human exposure in China.