We studied the effects of chronic exposure to metals on energy reserves and reproduction in the clam Megapitaria squalida in two nearby populations exposed to different levels of pollution from mining operations in the Gulf of California, Mexico. Female M. squalida from San Lucas beach had good reproductive health status, whereas Santa Rosalia specimens consistently showed low energy reserves, massive oocyte resorption throughout the year, high frequencies of undifferentiated individuals, low proportions of ripe and spawning organisms, smaller and fewer oocytes per follicle, and significantly lower follicular areas. Ovarian levels of Co, Cu, Pb, Mn, and Zn were consistently higher in clams from Santa Rosalia. The poor reproductive health of clams inhabiting this site may be attributed to their long-term exposure to high Co, Cu, and Pb concentrations, as these have been shown to cause toxicity and reproductive impairments in other marine organisms.

Global climate change has attracted worldwide attention. The ocean is the largest active carbon pool on the planet and plays an important role in global climate change. However, marine plastic pollution is getting increasingly serious due to the large consumption and mismanagement of global plastics. The impact of marine plastics on ecosystem responsible for the gas exchange and circulation of marine CO₂ may cause more greenhouse gas emissions. Consequently, in this paper, threats of marine microplastics to ocean carbon sequestration are discussed. Marine microplastics can 1) affect phytoplankton photosynthesis and growth; 2) have toxic effects on zooplankton and affect their development and reproduction; 3) affect marine biological pump; and 4) affect ocean carbon stock. Phytoplankton and zooplankton are the most important producer and consumer of the ocean. As such, clearly, further research should be needed to explore the potential scale and scope of this impact, and its underlying mechanisms.

The anthropogenic impact in the Wouri Estuary Mangrove located in the rapidly developing urban area of Douala, Cameroon, Africa, was studied. A set of 45 Persistent Organic Pollutant were analysed in surficial mangrove sediments at 21 stations. Chlorinated Pesticides (CLPs), Polychlorinated Biphenyls (PCBs) and Polycyclic Aromatic Hydrocarbons (PAHs) have concentrations ranging from 2.2 – 27.4, and 83 – 544 ng/g, respectively. The most abundant CLPs were endosulfan, alachlor, heptachlor, lindane (γ-HCH) and DDT, which metabolites pattern revealed recent use. Selected PAHs diagnostic ratios show pyrolytic input predominantly. The sum of 7 carcinogenic PAHs (ΣC-PAHs) represented 30 to 50% of Total PAHs (TPAHs). According to effect-based sediment quality guidelines, the studied POPs levels imply low to moderate predictive biological toxicity. This study contributes to depict how far water resources are shifting within what is now termed the Anthropocene due to increasing local pressures in developing countries or African countries.

PURPOSE OF REVIEW: The purpose of this review is to summarize the current understandings of atmospheric VOC characteristics in China and put forward the methodological drawbacks of the VOC measurement that need to be resolved and the research gaps that need to be filled. RECENT FINDINGS: Whereas in recent investigations in the North China Plain (NCP) a reduction (20–66%) in total VOC concentration is noticed compared with the ones published before 2015, an increase (13–127%) is observed for the Yangtze River Delta (YRD) region. Aromatics and oxygenated VOCs are frequently appearing as the most abundant VOC group in recent investigations. Industry-related VOC sources are more dominant in the YRD regions while vehicle-related sources are more influential in the NCP, Central China, and Pearl River Delta regions. Benzene, 1,3,5-trimethylbenzene, ethylbenzene, naphthalene, dichloromethane, 1,2-dichloroethane, 1,2-dichloropropane, chloroform, carbon tetrachloride, and 1,2-dibromoethane pose carcinogenic risk to exposed population in China and the most risk-prone areas are affected by the petrochemical industry, biomass burning, waste management, and vehicle emissions. Formaldehyde and toluene have relatively high concentrations among the different indoor VOCs observed and their concentrations noticed to be exceeded the national air quality standard. More investigations have to be performed on rarely studied health risk assessment of VOCs and characterization of indoor VOCs. BVOC studies are rarely conducted in China, which has to be performed on common plant species, different forest, and agricultural crops. VOC characterization in forest fire smokes and more process-specific emission characteristics in common industries need to be conducted.

Previous laboratory feeding experiments, representing the state-of-the-art methodology to investigate microplastic (MP) ingestion and its impact for fish, tend to disregard both the significance of applying realistic MP densities and the potential relevance of biofilm-coating for ingestion probability. This experiment assessed the uptake of either pristine or biofilm-coated MP particles and the physiological impacts for juvenile white seabream for MP concentrations consistent with those found in the field along with natural prey over a course of 3.5 weeks. Results indicate the ability of juvenile D. sargus to discriminate between edible and non-edible prey. A distinct preference for biofilm-coated over pristine particles could not be verified. No significant impact on growth and condition was found except for high levels of MP ingestion. The outcomes highlight the importance of performing MP feeding experiments mimicking natural conditions to reliably assess the impact of MP on early life stages of fish.

This study examined the marine environment and seafood safety using chemical monitoring and multiple biomarkers. Samples were collected from three bays on the Shandong Peninsula in China, Laizhou, Rushan and Jiaozhou, in March, May, August, and October of 2018 and 2019. The polycyclic aromatic hydrocarbon (PAH) concentrations in sediments and tissue samples from the clam Ruditapes philippinarum and multiple biomarkers were measured. All the sampling sites were found to be medium-PAH-contaminated areas (100–1000 ng/g d.w.). According to the correlation analysis, ethoxyresorufin-o-deethylase (EROD) and superoxide dismutase (SOD) activity in the clam's digestive gland were sensitive to PAHs (p < .05), but the incremental lifetime cancer risk (ILCR) was lower than the priority risk level (10⁻⁴) at most sampling sites. EROD, SOD and acetylcholinesterase activity exhibited significant correlations with the ILCR values (p < .01), suggesting that they may serve as good indicators for assessing safe seafood consumption levels for human beings.

We examine the use of surrogates in the measurement of concentrations of polycyclic aromatic hydrocarbons (PAH) in marine sediment, consider shortcomings of current interpretations of the results from this widely used approach, and propose an alternative data treatment. We focus on the current common practice of accepting all data within a predefined range of acceptable recoveries as equally valid and propose treating surrogate recovery data as one component of measurement uncertainty. Our analysis leads us to conclude that the more uniform surrogate recoveries are, the more justified the assumption that they reveal measurement bias and appropriately can be used as corrections; but that the less uniform recoveries are, the greater the need to treat them as a source of measurement uncertainty. We recognize that acceptance of the ideas presented here will require much thought and refinement by the environmental analytical community. We welcome a thorough discussion.

As part of the Deepwater Horizon Oil Spill Natural Resource Damage Assessment in the Gulf of Mexico, we conducted a large passive acoustic survey across the eastern Gulf continental shelf edge to assess impacts to sperm whale population. In the months immediately after the spill, sperm whale occurrence was significantly higher in areas closest to the spill. Over the following seasons in 2010–2011, we documented cyclical patterns of decreased and increased occurrence suggesting that this population exhibits a seasonal occurrence pattern in the region, with seasonal movements to other regions, and not likely directly influenced by the oil spill. Unfortunately, a lack of adequately scaled, pre-spill data on sperm whales, along with limitations on the survey duration constrain our ability to infer spill-related changes in sperm whale occurrence. However, our study establishes post-disaster baseline data for continued monitoring, and an expanded study design could provide a model for continued monitoring.

Microplastics have received special attention due to their potential risks to environments. However, data on microplastics in estuaries of the Southeast Asian region is still insufficient. This study investigated the abundance and characteristics of microplastics in the sediment and surface water of the Chao Phraya River Estuary, Thailand. Concentrations of heavy metals extracted from microplastics were also reported. The abundance of microplastics in surface water and sediment was 48 ± 8 items/m³ and 39 ± 14 items/kg, respectively. Microplastics with small sizes of 0.05–0.3 mm were predominant in all collected samples. Polypropylene and polyethylene particles were the most abundant in the surface water and sediment, respectively. Toxic metals (Cr, Cu, Ni, Pb, Cd, and Zn) were found in microplastics from surface water samples. Since Chao Phraya River Estuary is an important aquaculture zone in Thailand, the presence of microplastics in this area may severely impact on aquaculture and human health.

The effects of microplastic fibers (MPF) on the survival, molting and oxygen consumption rates of larval (I-III) and post-larval (IV) stages of the American lobster, Homarus americanus, were quantified as a function of MPF concentration and food availability. Only the highest MPF concentration decreased early larval survival. MPF did not affect the timing or rate of molting across MPF treatments. While all larval and post-larval stages accumulated MPF under the cephalothorax carapace, stage II larvae and stage IV post-larvae showed the highest and lowest accumulation, respectively. MPF ingestion increased with larval stage and with MPF concentration; under starvation conditions, stage I larvae only ingested them at low MPF concentrations. Oxygen consumption rates were lower only in later larval stages when exposed to high MPF concentrations. Combined, our results indicate that MPF interactions and effects on American lobster larvae are dependent on larval stage, MPF concentration, and presence of food.