Multi-level responses of oysters Crassostrea virginica for assessing organochlorine pesticides in a Ramsar coastal lagoon in southern Mexico

Polycyclic aromatic hydrocarbons during the 21st Century in Southern Gulf of Mexico, a prominent petroleum area: A review

Petroleum industry in the southern Gulf of Mexico possesses relevant importance for the Mexican economy but it has also impacted the marine and coastal environments of this region. The objective of the current review is to provide a substantial panorama of the polycyclic aromatic hydrocarbons (PAHs) during the XXI century. The highest PAHs concentration in water was found in the Dos Bocas Maritime Terminal and the Mecoacán Lagoon; sediments and cores were found in Sontecomapan, Mandinga, and La Mancha Lagoons; maximum PAHs levels in biota were found in fish in Términos Lagoon. PAHs in water and oysters were comparable to others around the world; sediments concentrations were higher than in other regions. Mecoacán Lagoon, coastal shelf Tamaulipas, and Cayo Arcas Reef Complex showed a higher risk estimation based on sediment concentrations. It is necessary to establish monitoring programs in the study region due to the trends found in PAHs.

Association Between Prenatal Exposure to Organochlorine Pesticides and Telomere Length in Neonatal Cord Blood

Objectives: Environmental exposure may affect the telomere length (TL) of newborns, which is considered as an early biomarker indicating susceptibility for later life diseases. However, the effects of prenatal organochlorine pesticide (OCP) exposure on newborn TL remain unclear. This study aimed to investigate the association between prenatal exposure levels of OCPs during pregnancy and TL in neonatal cord blood. Methods: A total of 168 mother-infant pairs from a birth cohort in Wuhan, China, were included this study. The concentrations of hexachlorocyclohexanes (HCHs, including β-HCH, α-HCH, and γ-HCH), p,p'-dichlorodiphenyltrichloroethane (p,p'-DDT) and its metabolites (p,p'-dichlorodiphenyldichloroethane, p,p'-DDD; p,p'-dichlorodiphenyldichloroethylene, p,p'-DDE) were measured in cord blood. The associations between the OCPs and the TL in newborns were analyzed by a generalized linear regression model. Stratified analyses by newborn sex, maternal gestational weight gain, and pregnancy body mass index (BMI) were performed to evaluate if the associations were modified by these factors. Results: The detection rates of various OCPs ranged from 50.9% to 100.0%. The median concentration of p,p'-DDE was the highest (33.90 ng/g lipid), followed by β-HCH (8.67 ng/g lipid), and the median concentrations of the other OCPs were between 0.12 and 0.33 ng/g lipid. Among the all newborns, a two-fold increase in the γ-HCH concentration in the cord blood was significantly associated with a 0.024 (95% CI: -0.041, -0.007) decrease in the TL. After stratification by newborn sex, the inverse association between γ-HCH and the TL was only statistically significant in boys, but not in girls (P for interaction <0.05). In addition, after stratification by pre-pregnancy BMI, β-HCH and p,p'-DDT concentrations were significantly associated with a decreased TL in the overweight pre-pregnancy BMI group [-0.111 (95% CI: -0.203, -0.018) and -0.036 (95% CI: -0.049, -0.023), respectively]. Conclusions: Prenatal exposure to OCPs during pregnancy was associated with a decreased neonatal telomere length, which may be affected by the newborn sex and pre-pregnancy BMI. These findings may provide new insights into the mechanisms underlying OCP-induced adverse health effects.

Spatial distribution of PAHs, nickel, and vanadium in sediments from a large coastal lagoon near a petroleum extraction area in the southern Gulf of Mexico

One of the world's crucial areas for crude oil exploration and extraction is the southern Gulf of Mexico, where Terminos Lagoon (TL) is located. Sediments from the TL region were used to assess the spatial patterns, origins, and ecotoxicological risks associated with 16 priority polycyclic aromatic hydrocarbons (PAHs; 3.1-248.9 ng⸳g-1 dry weight basis, dw) and trace metals (Ni = 11.0-104.0 mg⸳kg-1; V = 2.0-35.0 mg⸳kg-1 dw) linked to anthropogenic activities. Although origin indices based on PAHs and metals concentrations indicate no crude oil pollution in the region, sources of pyrogenic PAHs were identified. A chemometric approach demonstrated associations between organic matter and PAHs, and that metal accumulation depends mostly by the input of lithogenic materials. Ecotoxicological risk estimations showed a higher risk of possible adverse effects in sites near swamps and mangrove zones, highlighting the need of future monitoring. This study provides a reference for policymakers to conserve Mexico's largest coastal lagoon and other oil-impacted coastal areas worldwide.

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.

Assessment of coastal pollutants and health status of Pacific oysters (Magallana gigas) in the Bahía Blanca Estuary and adjacent beaches (Argentina)

This study assessed the effects of pollutants on Magallana gigas along a coastal zone with different levels of human activity: a highly impacted zone in the Bahía Blanca Estuary and a less impacted zone on the adjacent sandy beaches. Oysters collected in 2021 were analyzed for various factors, including metals, polycyclic aromatic hydrocarbons (PAHs), organochlorine pesticides, microplastics, oxidative stress and histology. Oysters of both environments exhibited detectable concentrations of all these pollutants in their tissues. However, the estuarine oysters showed higher concentrations of Zn, Cu and As and total PAHs than the beach oysters. Banned organochlorine pesticides were detected only in beach oysters. Estuarine oysters displayed morphological changes in their digestive gland including a reduction in the mean epithelial thickness of the tubule and elevated lipid peroxidation levels, indicating cellular damage. This study underscores the widespread presence of pollutants in M. gigas, indicating the need for effective strategies to safeguard coastal ecosystem health.

Biochemical and physiological alterations caused by Diuron and Triclosan in mussels (Mytilus galloprovincialis)

The rise in the utilization of pesticides within industrial and agricultural practices has been linked to the occurrence of these substances in aquatic environments. The objective of this work was to evaluate the uptake and adverse impacts of Diuron (Di) and Triclosan (TCS) on the mussel species Mytilus galloprovincialis. To accomplish this, the accumulation and toxicity of these pesticides were gauged following a brief period of exposure spanning 14 days, during which the mussels were subjected to two concentrations (50 and 100 μg/L) of each substance that are ecologically relevant. Chemical analysis of Di and TCS within gills and digestive gland showed that these pesticides could be accumulated in mussel's tissues. In addition, Di and TCS are preferably accumulated in digestive gland. Measured biomarkers included physiological parameters (filtration FC and respiration RC capacity), antioxidant enzyme activities (superoxide dismutase and catalase), oxidative damage indicator (Malondialdheyde concentration) and neurotoxicity level (acetylcholinesterase activity) were evaluated in gills and digestive glands. Both pesticides were capable of altering the physiology of this species by reducing the FC and RC in concentration and chemical dependent manner. Both pesticides induced also an oxidative imbalance causing oxidative stress. The high considered concentration exceeded the antioxidant defense capacity of the mussel and lead to membrane lipid peroxidation that resulted in cell damage. Finally, the two pesticides tested were capable of interacting with the neuromuscular barrier leading to neurotoxicity in mussel's tissues by inhibiting acetylcholinesterase. The ecotoxicological effect depended on the concentration and the chemical nature of the contaminant. Obtained results revealed also that the Di may exert toxic effects on M. galloprovincialis even at relatively low concentrations compared to TCS. In conclusion, this study presents innovative insights into the possible risks posed by Diuron (Di) and Triclosan (TCS) to the marine ecosystem. Moreover, it contributes essential data to the toxicological database necessary for developing proactive environmental protection measures.

A systematic review on the current situation of emerging pollutants in Mexico: A perspective on policies, regulation, detection, and elimination in water and wastewater

Emerging pollutants (EPs) emerged as a group of new compounds whose presence in the environment has been widely detected in Mexico. In this country, different concentrations of pharmaceutical compounds, pesticides, dyes, and microplastics have been reported, which vary depending on the region and the analyzed matrix (i.e., wastewater, surface water, groundwater). The evidence of the EPs' presence focuses on the detection of them, but there is a gap in information regarding is biomonitoring and their effects in health in Mexico. The presence of these pollutants in the country associated with lack of proper regulations in the discharge and disposal of EPs. Therefore, this review aims to provide a comprehensive view of the current environmental status, policies, and frameworks regarding Mexico's situation. The review also highlights the lack of information about biomonitoring since EPs are present in water even after their treatment, leading to a critical situation, which is high exposure to humans and animals. Although, technologies to efficiently eliminate EPs are available, their application has been reported only at a laboratory scale thus far. Here, an overview of health and environmental impacts and a summary of the research works reported in Mexico from 2014 to 2023 were presented. This review concludes with a concrete point of view and perspective on the status of the EPs' research in Mexico as an alert for government entities about the necessity of measures to control the EPs disposal and treatment.

Targets for pollutants in rat and human pancreatic beta-cells: The effect of prolonged exposure to sub-lethal concentrations of hexachlorocyclohexane isomers on the expression of function- and survival-related proteins

Decades after most countries banned hexachlorocyclohexane, HCH isomers still pollute the environment. Many studies described HCH as a pro-diabetic factor; nevertheless, the effect of HCH isomers on pancreatic beta-cells remains unexplored. This study investigated the effects of a one-month exposure to α-HCH, β-HCH, and γ-HCH on protein expression in human (NES2Y) and rat (INS1E) pancreatic beta-cell lines. α-HCH and γ-HCH increased proinsulin and insulin levels in INS1E cells, while β-HCH showed the opposite trend. α-HCH altered the expression of PKA, ATF3, and PLIN2. β-HCH affected the expression of GLUT1, GLUT2, PKA, ATF3, p-eIF2α, ATP-CL, and PLIN2. γ-HCH altered the expression of PKA, ATF3, PLIN2, PLIN5, and IDH1. From the tested proteins, PKA, ATF3, and PLIN-2 were the most sensitive to HCH exposure and have the potential to be used as biomarkers.

Organochlorine contaminants in sediments and factors influencing their distribution in the natural marine protected area in the gulf of Mexico

The aim of this study was to determine the concentration of polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) in marine sediments of a natural marine protected area (NMPA), Veracruz Reef System (VRS), in the Gulf of Mexico (GoM). This NMPA represents one of the first coastal sites with port activity in Mexico, which causes a range of human activities that require adequate planning so as not to impact and destroy this marine protected area; In this sense, this work represents the first effort aimed at diagnosing the presence of organochlorine contaminants in reef sediments from the mainland, both from the adjacent port area and from more distant regions with dominant agricultural activities that ultimately affect this NMPA. Content of organic matter (OM), carbonates and grain-size composition were determined to investigate their influence on compounds distribution in the sediment through multivariate analysis. The potential risk represented by organochlorines concentrations was evaluated taking as reference Sediment Quality Guidelines (SQGs). Levels of ∑PCBs, ∑DDTs, ∑HCHs and ∑Cyclodienes ranged from 11.59 to 29.79, < 0.01 to 34.11, 22.10 to 102.80, and 17.21-104.45 ng g-1 dry weight (DW), respectively. The statistical analysis revealed that the content of mud and organic matter were the parameters that might influence PCBs distribution in the sediment while OCPs could be influenced by sand and carbonate. The theoretical risk assessment estimated with the results obtained showed that concentrations of lindane, endrin, dieldrin and p,p'-DDT could have an adverse effect on the reef benthic community and continued monitoring is required. The data obtained on the organochlorine contaminants (OCs) considered in this work will contribute to support the strategies proposed by the Mexican federal government entity to continue with the conservation and surveillance of this NMPA and thereby guarantee the least impact derived mainly from port and related agricultural activities.