Health impacts of consuming shellfish contaminated with polycyclic aromatic hydrocarbons (PAHs), harvested from waters polluted by petroleum and industrial activities

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous toxic chemicals in the environment. Human activities have resulted in water pollution and seafood contamination with PAHs. PAHs bioaccumulate in shellfish, and their ingestion leads to several health outcomes. However, the extent of contamination and actual risk to shellfish consumers is not widely known. Therefore, the primary goal of this thesis is to highlight the health impacts of this consumption by synthesizing the evidence related to the health impacts of PAHs oral exposure, shellfish contamination across the world, and the degree of risk imposed on consumers. Two Cochrane-style systematic reviews were conducted: a review on the health effects of oral exposure to PAHs; another review on shellfish PAH contaminations, and risk assessments globally; and methodological reflections from collaborative research in Burrard Inlet assessing shellfish contamination and health risk to consumers from the Tsleil-Waututh Nation. The first systematic review confirmed cancer, developmental defects, toxicities in the nervous system, immune system, endocrine system, reproductive system, heart, and liver, following PAHs oral exposure. The second review showed different ranges of shellfish contamination worldwide. Based on the risk assessments, shellfish harvested from 40% of the studied areas imposed considerable risks on consumers. In Burrard Inlet, PAH levels were measured in several samples that suggested elevated risk while identifying methodological complexities in defining the implications of these findings. This review showed high risks for consumers due to shellfish PAH contamination across many countries, which may be associated with serious health impacts. In addition to using more rigorous methodological approaches in evaluating contamination, unique characteristics of each population need to be acknowledged in risk assessments.Medicine, Faculty ofPopulation and Public Health (SPPH), School ofGraduat