Contamination of typical phthalate acid esters in surface water and sediment of the Pearl River, South China: Occurrence, distribution, and health risk assessment

Air-Sea Exchange and Atmospheric Deposition of Phthalate Esters in the South China Sea

Phthalate esters (PAEs) have been investigated in paired air and seawater samples collected onboard the research vessel SONNE in the South China Sea in the summer of 2019. The concentrations of ∑₇PAEs ranged from 2.84 to 24.3 ng/m³ with a mean of 9.67 ± 5.86 ng/m³ in air and from 0.96 to 8.35 ng/L with a mean of 3.05 ng/L in seawater. Net air-to-seawater deposition dominated air-sea exchange fluxes of DiBP, DnBP, DMP, and DEP, while strong water-to-air volatilization was estimated for bis(2-ethylhexyl) phthalate (DEHP). The estimated net atmospheric depositions were 3740 t/y for the sum of DMP, DEP, DiBP, and DnBP, but DEHP volatilized from seawater to air with an average of 900 t/y. The seasonally changing monsoon circulation, currents, and cyclones occurring in the Pacific can significantly influence the concentration of PAEs, and alter the direction and magnitude of air-sea exchange and particle deposition fluxes. Consequently, the dynamic air-sea exchange process may drive the transport of PAEs from marginal seas and estuaries toward remote marine environments, which can play an important role in the environmental transport and cycling of PAEs in the global ocean.

Occurrence and seasonal disparity of emerging endocrine disrupting chemicals in a drinking water supply system and associated health risk

Contamination of drinking water with endocrine-disrupting chemicals (EDCs) raises concerns over the security and long-term sustainability of clean water supplies as well as human exposure via daily water intake. In this study, the seasonal disparity and occurrence of six phthalates and bisphenol-A in the drinking water supply system and associated health-risk were examined. The detection frequencies of the ∑6PAEs ranged from 24 to 100% in the winter whereas; in summer it is below the detection limit up to 100%. DEHP was the most prevalent phthalate congener ranging from 1.14 to 8351.85 µg/L (winter) and 0.552 to 410.29 µg/L (summer) surpassing the permissible limit. However, BPA concentrations were found under the permissible limit. The results suggested that PAEs concentration displayed significant seasonal variations with the highest in winter and the lowest in summer. The exposure to PAEs and BPA from drinking water was assessed, indicating a possible health risk to humans with a hazard quotient (HQ) > 1 for DEHP only. The findings necessitate an immediate scrutiny of these EDCs in drinking water supply system and are critical for implementing effective technologies at the WTP scale to ensure the quality and safety of drinking water to ascertain human and environmental health.