Characterization of persistent organic contaminants in the atmosphere of Gadani's ship breaking yards and its surrounding: Implications for sustainable ship recycling practices

Gadani is internationally renowned for its extensive ship -breaking operations, positioning it as one of the globe's primary ship -breaking hubs. A comprehensive study was conducted to evaluate the presence of organic contaminants in the air within Gadani, encompassing the areas surrounding ship -breaking facilities, proximate residential settlements, and adjacent roadways. Passive air samplers were employed to collect a total of 30 air samples. The analytical results unveiled a notably elevated concentration of specific organic compounds, with a pronounced prevalence of polycyclic aromatic hydrocarbons (PAHs), short -chain chlorinated paraffins (SCCPs), and polychlorinated biphenyls (PCBs) at the ship -breaking yard. Notably, dichlorodiphenyltrichloroethanes (DDTs) and DDE were detected at substantially lower levels. In particular, sites in close proximity to shipbreaking activities exhibited elevated concentrations of PCBs (Sigma 7PCB 0.065429 to 7.345714 ng/sample), PAHs (Sigma 8PAH 2.44 to 134.23 ng/sample), and SCCPs (0.18 to 25.6 ng/sample). Conversely, DDTs and DDE demonstrated higher concentrations near residential settlements. The evaluation of Molecular Diagnostic Ratios for PAHs revealed anthracene/anthracene + phenanthrene ratios of 0.88, 0.69, and 0.5 for ship -breaking areas, roadside locations, and community surroundings, respectively. Furthermore, the benz[a]anthracene/benz-[a] anthracene + chrysene molecular ratios were measured at 0.77 (ship -breaking sites), 0.82 (roadside), and 0.83 (community), respectively. The molecular ratio of fluoranthene/fluoranthene + pyrene at ship -breaking sites was 0.23, while roadside and community ratios were 0.36 and 0.89, respectively. These findings underscore the significant contribution of ship -recycling activities to the atmospheric release of SCCPs, PCBs, and PAHs, emphasizing the global imperative for responsible ship recycling practices.