Dichlorodiphenyltrichloroethane (DDT) and Dichlorodiphenyldichloroethylene (DDE) levels in air and surface sea waters along the Antarctic Peninsula

Assessment of cancer and dietary risks in commercially valuable marine organisms in coast of a region of future exploration (Equatorial South Atlantic)

The Equatorial South Atlantic region, spanning over 1700 km, is currently undergoing extensive exploitation through various activities such as oil extraction, desalination plants, marine mineral explorations, and wind power for green hydrogen production. This undoubtedly also contributes to the exacerbation of pre-existing chronic environmental impacts. This study aims to investigate the concentrations of 60 substances, categorized as Persistent Organic Pollutants (POPs) and Contaminants of Emerging Concern (CECs) from various classes including: polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), organochlorine pesticides (OCPs), as well as Pyrethroids (PPs), Triazines (TPs) and Organophosphates (OPPs) pesticides in consumable fish, shellfish, and crabs. The bivalve (Mytella charruana), crab (Ucides cordatus), and catfish (Sciades herzbergii) samples were collected in areas of ecological, environmental and economic importance. This data was used to estimate concentrations in the organisms, and to calculate cancer and human health risk. The most prevalent pollutant classes in the organisms were OCPs, followed by TPs and PPs. Shellfish and fish samples had more compounds indicating health risks, when compared to crabs. The substances causing cancer risks varied across organisms and study areas. The heightened cancer risks linked to specific compounds in various species highlight the urgent need to address persistent pollutants to prevent long-term health impacts on both humans and wildlife. Compounds such as PPs, TPs, and OPPs pose significant risks of neurotoxicity and endocrine disruption. This study underscores the interconnectedness of environmental and human health in coastal ecosystems, calling for continuous monitoring and adaptive management strategies to protect these fragile environments and the communities that rely on them.

Indirect Impact of Eutrophication on Occurrence, Air-Water Exchange, and Vertical Sinking Fluxes of Antibiotics in a Subtropical River

A significant challenge that warrants attention is the influence of eutrophication on the biogeochemical cycle of emerging contaminants (ECs) in aquatic environments. Antibiotics pollution in the eutrophic Pearl River in South China was examined to offer new insights into the effects of eutrophication on the occurrence, air-water exchange fluxes (Fair-water), and vertical sinking fluxes (Fsinking) of antibiotics. Antibiotics transferred to the atmosphere primarily through aerosolization controlled by phytoplankton biomass and significant spatiotemporal variations were observed in the Fair-water of individual antibiotics throughout all sites and seasons. The Fsinking of ∑AB14 (defined as a summary of 14 antibiotics) was 750.46 ± 283.19, 242.71 ± 122.87, and 346.74 ± 249.52 ng of m-2 d-1 in spring, summer, and winter seasons. Eutrophication indirectly led to an elevated pH, which reduced seasonal Fair-water of antibiotics, sediment aromaticity, and phytoplankton hydrophobicity, thereby decreasing antibiotic accumulation in sediments and phytoplankton. Negative correlations were further found between Fsinking and the water column daily loss of antibiotics with phytoplankton biomass. The novelty of this study is to provide new complementary knowledge for the regulation mechanisms of antibiotics by phytoplankton biological pump, offering novel perspectives and approaches to understanding the coupling between eutrophication and migration and fate of antibiotics in a subtropical eutrophic river.

DDT and titanium dioxide nanoparticle coexposure induced neurobehavioral deficits in zebrafish

Both dichlorodiphenyltrichloroethane (DDT) and titanium dioxide nanoparticle (TiO2 NP) have worldwide-scale commercial applications, resulting in their co-pollution in the ecosystems and posing combined health risks. However, there is a lack of toxicity studies for the interactions of DDT and TiO2 NP in the environmental relevant concentrations. In this study, we characterized the coexposures using a zebrafish waterborne exposure approach and evaluated the neurotoxicity response of the treated embryos or adults. Our results showed that DDT/TiO2 NP coexposure enhanced the DDT accumulation in vivo and increased the larval locomotor. The chronic DDT/TiO2 NP coexposure did not affect the overall survival rate, sex ratio and growth. However, DDT/TiO2 NP coexposure severely affected the adult locomotor activity, social contact, shoaling and aggressive behaviors compared to single treatment groups or controls. These adult behavioral deficits were accompanied by changes in neurotransmitter acetylcholine (ACH) level in the brain and muscle tissues, as well as neural development genes expression activation of growth-associated protein 43 (gap43) and synaptic vesicle glycoprotein 2 (sv2) in the brain. The significantly increased ACH level and the activated neural genes expression in the DDT/TiO2 NP co-exposed fish may account for the observed hyperactivity and social deficits.