Characterization and quantification of atmospheric emissions of dioxins, dl-PCBs and polycyclic aromatic hydrocarbons from municipal solid waste open burning in Southeast Asia

Abstract

Solid waste open burning is an important source of dioxins and other toxic pollutants that have not been sufficiently characterized. This study investigated atmospheric emissions of semi-volatile organic compounds (SVOCs) from municipal solid waste open burning (MSWOB) and mixed plastics burning in unconfined loose piles. Emission factors (EF) of 17 chlorinated dioxins, 12 dioxin-like polychlorinated biphenyls (dl-PCBs), and 13 polycyclic aromatic hydrocarbons (PAHs) varied between experiments owing to changing waste types and combustion conditions. Average EFs for MSWOB on a wet weight basis of the waste materials for dioxins and dl-PCBs were 482 and 32 ng WHO-TEQ/kg, respectively, and 66 mg/kg for PAHs. Corresponding values for plastics burning were 9.6 and 0.55 ng WHO-TEQ/kg, and 31 mg/kg. The gas phase dominated over the particulate phase, sharing above 70 % in the total of dioxins and dl-PCBs, respectively, and 90 % of PAHs emitted from MSWOB. The obtained SVOC congener distributions profiles show the signatures of waste burning sources, with prominent markers of de novo formed dioxins. The obtained EFs, reported for the first time for waste burning practice in Southeast Asia, were used to produce order-of-magnitude annual emission estimates from MSWOB in the region, with 5.3 TEQ kg for dioxins and 669,400 kg for PAHs, including 5,221 kg benzo(a)pyrene and 268 kg dibenzo(a,h)anthracene. Background air showed similar SVOCs profiles, but at lower levels than burning smoke. Exposure to ambient air contaminated with the MSWOB emissions would cause adverse health effects. Strict regulations and stakeholders’ collective actions are required to stop this practice.