Human health risks due to airborne polychlorinated biphenyls are highest in New Bedford Harbor communities living closest to the harbor

Narrative of hazardous chemicals in water: Its potential removal approach and health effects

H₂O is essential for life to exist on earth; it is important to guarantee both the quality and supply of water to satisfy world demand. However, it became contaminated by a number of hazardous, inorganic industrial pollutants, which caused a number of issues like irrigation activities and unsafe human ingestion. Long-term exposure to harmful substances can result in respiratory, immunological, and neurological illnesses, cancer, and problems during pregnancy. Therefore, removing hazardous substances from wastewater and natural water sources is crucial. It is necessary to develop an alternate method that can effectively remove these toxins from water bodies, as conventional methods have several drawbacks. This review primarily aims to achieve the following goals: 1) to discuss the distribution of harmful chemicals: 2) to give specifics on numerous possible strategies for getting rid of hazardous chemicals, and 3) its effects on the environment and consequences for human health have been examined.

Aerobic Bioaugmentation to Decrease Polychlorinated Biphenyl (PCB) Emissions from Contaminated Sediments to Air

We conducted experiments to determine whether bioaugmentation with aerobic, polychlorinated biphenyl (PCB)-degrading microorganisms can mitigate polychlorinated biphenyl (PCB) emissions from contaminated sediment to air. Paraburkholderia xenovorans strain LB400 was added to bioreactors containing PCB-contaminated site sediment. PCB mass in both the headspace and aqueous bioreactor compartments was measured using passive samplers over 35 days. Time-series measurements of all 209 PCB congeners revealed a 57% decrease in total PCB mass accumulated in the vapor phase of bioaugmented treatments relative to non-bioaugmented controls, on average. A comparative congener-specific analysis revealed preferential biodegradation of lower-chlorinated PCBs (LC-PCBs) by LB400. Release of the most abundant congener (PCB 4 [2,2'-dichlorobiphenyl]) decreased by over 90%. Simulations with a PCB reactive transport model closely aligned with experimental observations. We also evaluated the effect of the phytogenic biosurfactant, saponin, on PCB bioavailability and biodegradation by LB400. Time-series qPCR measurements of biphenyl dioxygenase (bphA) genes showed that saponin better maintained bphA abundance, compared to the saponin-free treatment. These findings indicate that an active population of bioaugmented, aerobic PCB-degrading microorganisms can effectively lower PCB emissions and may therefore contribute to minimizing PCB inhalation exposure in communities surrounding PCB-contaminated sites.

Toxicity of polychlorinated biphenyls in aquatic environments - A review

The assessment of polychlorinated biphenyls (PCBs) and their congeners resulting from the pollution of all environmental media is inherently related to its persistence and ubiquitous nature. In principle, determination of this class of contaminants are limited to the determination of their concentrations in the various environmental matrices. For solving many problems in this context, knowledge of the emission sources of PCBs, transport pathways, and sites of contamination and biomagnification is of great benefit to scientists and researchers, as well as many regulatory organizations. By far the largest amounts of PCBs, regardless of their discharged points, end up in the soil, sediment and finally in different aquatic environments. By reviewing relevant published materials, the source of origin of PCBs in the environment particularly from different pollution point sources, it is possible to obtain useful information on the nature of different materials that are sources of PCBs, or their concentrations and their toxicity or health effects and how they can be removed from contaminated media. This review focuses on the sources of PCBs in aquatic environments and critically reviews the toxicity of PCBs in aquatic animals and plants. The review also assesses the toxicity equivalency factors (TEFs) of PCBs providing valuable knowledge to other scientists and researchers that enables regulatory laws to be formulated based on selective determination of concentrations regarding their maximum permissible limits (MPLs) allowed. This review also supplies a pool of valuable information useful for designing decontamination technologies for PCBs in media like soil, sediment, and wastewaters.

A nested case-control study of serum polychlorinated biphenyls and papillary thyroid cancer risk among U.S. military service members

BACKGROUND AND OBJECTIVES

Although polychlorinated biphenyls (PCBs) were banned decades ago, populations are continuously exposed to PCBs due to their persistence and bioaccumulation/biomagnification in the environment. Results from limited epidemiologic studies linking PCBs to thyroid cancer have been inconclusive. This study aimed to investigate the association between individual PCBs and PCB mixture and papillary thyroid cancer (PTC), the most common thyroid cancer histologic subtype.

METHODS

We carried out a nested case-control study including 742 histologically confirmed PTC cases diagnosed in 2000-2013 and 742 individually matched controls among U.S. military service members. Pre-diagnostic serum samples that were collected on average nine years before PTC diagnosis were used to measure PCB congeners by gas chromatography isotope dilution high resolution mass spectrometry (GC/ID-HRMS). Conditional logistic regression, Bayesian kernel machine regression (BKMR), and weighted quantile sum (WQS) regression were employed to estimate the association between single PCB congeners as well as their mixture and PTC.

RESULTS

Four PCB congeners (PCB-74, PCB-99, PCB-105, PCB-118) had significant associations and dose-response relationships with increased risk of PTC in single congener models. When considering the effects from all measured PCBs and their potential interactions in the BKMR model, PCB-118 showed positive trends of association with PTC. Increased exposure to the PCB congeners as a mixturewas also associated with an increased risk of PTC in the WQS model, with the mixture dominated by PCB-118, followed by PCB-74 and PCB-99. One PCB congener, PCB-187, showed an inverse trend of association with PTC in the mixture analysis.

DISCUSSION

This study suggests that exposure to certain PCBs as well as a mixture of PCBs were associated with an increased risk of PTC. The observed association was mainly driven by PCB-118, and to a lesser extent by PCB-74 and PCB-99. The findings warrant further investigation.

Environmental Chemicals: Integrative Approach to Human Biomonitoring and Health Effects

In recent decades, citizen awareness of toxic chemicals has been a topic of interest, particularly concerning national and international policy decision makers, expert/scientific platforms, and health protection organizations (WHO, UNEP, CDC, EFSA, IPEN, etc [...].

Developmental polychlorinated biphenyl (PCB) exposure alters voiding physiology in young adult male and female mice

The impact of developmental exposure to environmental chemicals on lower urinary tract function is not well understood, despite the fact that these chemicals could contribute to etiologically complex lower urinary tract symptoms (LUTS). Polychlorinated biphenyls (PCBs) are environmental toxicants known to be detrimental to the central nervous system, but their impact on voiding function in mouse models is not known. Therefore, we test whether developmental exposure to PCBs is capable of altering voiding physiology in young adult mice. C57Bl/6J female mice received a daily oral dose of the MARBLES PCB mixture for two weeks prior to mating and through gestation and lactation. The mixture mimics the profile of PCBs found in a contemporary population of pregnant women. Voiding function was then tested in young adult offspring using void spot assay, uroflowmetry and anesthetized cystometry. PCB effects were sex and dose dependent. Overall, PCBs led to increases in small size urine spots in both sexes with males producing more drop-like voids and greater peak pressure during a voiding cycle while females displayed decreases in void duration and intervoid interval. Together, these results indicate that developmental exposure to PCBs are capable of altering voiding physiology in young adult mice. Further work to identify the underlying mechanisms driving these changes may help develop more effective preventative or therapeutic strategies for LUTS.

The Bladder Is a Novel Target of Developmental Polychlorinated Biphenyl Exposure Linked to Increased Inflammatory Cells in the Bladder of Young Mice

Bladder inflammation is associated with several lower urinary tract symptoms that greatly reduce quality of life, yet contributing factors are not completely understood. Environmental chemicals are plausible mediators of inflammatory reactions within the bladder. Here, we examine whether developmental exposure to polychlorinated biphenyls (PCBs) leads to changes in immune cells within the bladder of young mice. Female mice were exposed to an environmentally relevant mixture of PCBs through gestation and lactation, and bladders were collected from offspring at postnatal day (P) 28-31. We identify several dose- and sex-dependent PCB effects in the bladder. The lowest concentration of PCB (0.1 mg/kg/d) increased CD45+ hematolymphoid immune cells in both sexes. While PCBs had no effect on CD79b+ B cells or CD3+ T cells, PCBs (0.1 mg/kg/d) did increase F4/80+ macrophages particularly in female bladder. Collagen density was also examined to determine whether inflammatory events coincide with changes in the stromal extracellular matrix. PCBs (0.1 mg/kg/d) decreased collagen density in female bladder compared to control. PCBs also increased the number of cells undergoing cell division predominantly in male bladder. These results implicate perturbations to the immune system in relation to PCB effects on the bladder. Future study to define the underlying mechanisms could help understand how environmental factors can be risk factors for lower urinary tract symptoms.

Spatial, temporal, and inter-compartmental environmental monitoring of lipophilic pollutants by virtual organisms

Sampling points belonging to the Harz National Park river system, Germany, were selected between the period of 2014 and 2017 for monitoring polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) in water, air, and sediment. Triolein-containing Virtual Organisms (VO) were employed to assess the levels of chemicals in water, air and triolein as surrogate for natural fat. To avoid overestimation of the concentrations 20 performance reference compounds (PRCs)-16 PRCs-PAHs and 4 PRCs-PCBs were covering the range of properties of native compounds. Results manifested the highest concentration of individual PAH as follows: 31 ng fluoranthene/L water, 3600 ng pyrene/g fat, 62 ng phenanthrene/m³ air and 2800 ng fluoranthene/g dw sediment. All PCBs and OCPs values were below above mentioned PAH concentrations and far below EU-limit levels. Environmental partition of chemicals was investigated by calculating fugacity, suggesting a mass transport from water to air. Only quite volatile compounds such as hexachlorobutadiene showed higher fugacity in air. Ratios of sediment/water concentrations and log Kow within individual sampling periods at Holtemme River exhibited strong linear relationships. Interestingly, during summer months of the years water and fat contents well correlate to the flow rates of Holtemme River. Our results show that VO can be successfully used as a tool for ongoing exposure assessment studies and predictions of worst case levels in food and nutrition.

Comprehensive Subchronic Inhalation Toxicity Assessment of an Indoor School Air Mixture of PCBs

Few in vivo inhalation studies have explored the toxicity of environmentally relevant mixtures of polychlorinated biphenyls (PCBs). The manufacture of industrial PCBs was banned in 1978, but PCBs continue to be formed in industrial and consumer products. Schools represent a significant source of airborne exposures to legacy and nonlegacy PCBs, placing children at risk. To evaluate the impact of these exposures, we generated an airborne mixture of PCBs, called the School Air Mixture (SAM), to match the profile of an older school from our adolescent cohort study. Female Sprague-Dawley rats were exposed either to SAM or filtered air in nose-only exposure systems, 4 h/day for 4 weeks. Congener-specific air and tissue PCB profiles were assessed using gas chromatography with tandem mass spectrometry (GC-MS/MS). PCB exposures recapitulated the target school air profile with a similarity coefficient, cos θ of 0.83. PCB inhalation yielded μg/g ∑209 PCB levels in tissues. Neurobehavioral testing demonstrated a modest effect on spatial learning and memory in SAM-exposed rats. PCB exposure induced oxidative stress in the liver and lungs, affected the maturational stages of hematopoietic stem cells, reduced telomerase activity in bone marrow cells, and altered the gut microbiota. This is the first study to emulate PCB exposures in a school and comprehensively evaluate toxicity.

Evidence Implicating Non-Dioxin-Like Congeners as the Key Mediators of Polychlorinated Biphenyl (PCB) Developmental Neurotoxicity

Despite being banned from production for decades, polychlorinated biphenyls (PCBs) continue to pose a significant risk to human health. This is due to not only the continued release of legacy PCBs from PCB-containing equipment and materials manufactured prior to the ban on PCB production, but also the inadvertent production of PCBs as byproducts of contemporary pigment and dye production. Evidence from human and animal studies clearly identifies developmental neurotoxicity as a primary endpoint of concern associated with PCB exposures. However, the relative role(s) of specific PCB congeners in mediating the adverse effects of PCBs on the developing nervous system, and the mechanism(s) by which PCBs disrupt typical neurodevelopment remain outstanding questions. New questions are also emerging regarding the potential developmental neurotoxicity of lower chlorinated PCBs that were not present in the legacy commercial PCB mixtures, but constitute a significant proportion of contemporary human PCB exposures. Here, we review behavioral and mechanistic data obtained from experimental models as well as recent epidemiological studies that suggest the non-dioxin-like (NDL) PCBs are primarily responsible for the developmental neurotoxicity associated with PCBs. We also discuss emerging data demonstrating the potential for non-legacy, lower chlorinated PCBs to cause adverse neurodevelopmental outcomes. Molecular targets, the relevance of PCB interactions with these targets to neurodevelopmental disorders, and critical data gaps are addressed as well.