Sources Of Persistent Organic Pollutants Research Articles

Persistent organic pollutants among seafood processing workers in West Greenland

The Greenlandic population is highly exposed to persistent organic pollutants (POPs) through the consumption of traditional marine food, including marine mammals. Central to Greenland's economy and cultural identity, the fishing industry employes about 15% of the working population.This study investigated POP exposure, including polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), and per- and polyfluoroalkyl substances (PFASs), among seafood processing workers at the Greenlandic west coast. We examined determinants for the POPs including age, smoking habits, ethnicity, and working place. Additionally, we explored the association between POPs and the prevalence of asthma, allergy, and lung function.With samples taken during 2016–2018, the study encompassed 382 workers, primarily of Inuit descent (93%), employed across three large factories located in Nuuk, Sisimiut, and Ilulissat, four smaller factories in settlements (Kangaatsiaq, Ikerasaarsuk, Sarfannguaq, Qeqertarsuaq), and four factory trawlers. Data collected include clinical examinations, questionnaires on ethnicity, occupational exposure status, health indicators, and smoking habits, and serum selenium and POP analyses. We used ANCOVA with adjustment for relevant confounders to assess differences in POPs between groups (e.g. ethnic groups and working place), and multiple linear and logistic regressions were used to assess associations between POPs and lung function, allergy and asthma.Significant differences in POPs were observed among ethnic groups; Faroese workers had the highest concentrations of lipophilic POPs (lipPOPs; PCBs and OCPs), while Inuit workers exhibited highest PFASs. All subsequent analyses were focused on the Inuit workers (n = 337). The PFASs were significantly higher in workers at small factories, followed by large factories and trawlers, whereas no differences were seen for lipPOPs. The differences between the working places were most likely due to differences in lifestyle and diet, but occupational exposures cannot be excluded.LipPOP and PFAS concentrations associated positively with selenium, and PFASs positively associated with lung function. However, upon adjustment of selenium, the associations between PFASs and lung function became non-significant and attenuated towards null. No significant associations were found between POPs and the prevalence of asthma or allergy.Compared to the general population in the same area and period, the seafood processing workers exhibited 2–6 times higher POP levels. The higher exposure level among seafood processing workers, as well as the difference across workplaces, underscore the need for further investigation of environmental and occupational sources of POPs in this population. These findings may contribute to future public health strategies and regulatory measures to reduce POP exposure in Arctic populations.

Organochlorine pesticides and polychlorinated biphenyls in sediments of the Lanzhou reach of Yellow River (China): Spatial distribution, sources and risk assessment

Knowledge about sediment levels and sources of persistent organic pollutants (POPs) in Lanzhou section Yellow River remains limited. Organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) levels in 12 sediment samples from this region were measured by GC/MS. OCPs concentrations ranged from 85.6 to 202 ng/g, while PCBs levels varied between 3.08 and 32.3 ng/g. Our findings demonstrated a significant correlation between these pollutants and total organic matter (TOC), highlighting TOC's role in pollutants distribution. Notably, OCPs and PCBs levels were higher in the eastern section, following the water flow direction. The primary OCPs components were hexachlorocyclohexane (HCH) and dichlorodiphenyltrichloroethane (DDT), whereas PCBs were dominated by perchlorinated compound. Source identification indicated that OCPs primarily originated from historical residues and recent applications, while industrial activities as significant PCBs sources. Sediment quality guidelines and health risk assessments indicated negligible environmental risk. This study providing valuable insights on sediment pollution control and management strategies.

Pollution Assessment with Persistent Organic Pollutants in Upper Soil of a Series of Rural Roma Communities in Transylvania, Romania, Its Sources Apportionment, and the Associated Risk on Human Health

This paper aims to assess the pollution by determining the sources of persistent organic pollutants (POPs) in 22 rural Roma communities in Transylvania in order to assess the human health risk associated with this exposure. For this, 16 polycyclic aromatic hydrocarbons (PAHs), 20 organochlorine pesticides (OCPs) and 12 polychlorinated biphenyls (PCBs) were determined in 22 soil samples collected from selected areas by gas chromatography coupled with mass spectrometry for PAHs and with electron capture detector for all halogenated compounds. Target compounds were isolated from soil by ultrasound-assisted extraction. We found that POP concentrations in soil ranged from 4.86 to 451.85 ng/g dw for PAHs, from 25.62 to 139.30 ng/g dw for OCPs, and from 0.22 to 49.12 ng/g dw for PCBs. The diagnostic ratios ƩLMW/ƩHMW, ANT/(ANT + PHE), and FLT/(FLT + PYR) strongly suggest a pyrogenic model of PAHs, such as biomass, coal, and petroleum combustion, while the isomer ratios ƩDDT/ƩHCH, α-HCH/γ-HCH and (DDE + DDD)/ƩDDT suggest that OCP residues originate from their ancient uses. Non-carcinogenic (HI) and carcinogenic (CR) risks of these organic compounds present in the soil through non-dietary pathways were in the very low-risk category (ranging from 10−8 to 10−4), indicating an absence of these risks from the investigated POPs in the studied area.

Concentration and sources of persistent organic pollutants within the vicinity of a scrap-iron smelting plant: Seasonal pattern and health risk assessment

Polychlorinated biphenyls (PCBs) are a class of ubiquitous and significant synthetic organic chemicals that pose deleterious threats to the environment and human health. This study examined the concentration, indoor-outdoor and seasonal change, sources, and health effects of PCBs in particulate-bound dust near a scrap iron recycling plant. PCBs levels were determined in samples using gas chromatograph mass spectrometer. The results indicated that 5 Cl atoms PCB constituted the majority of PCBs (41% overall), contributing 43% during the rainy season and 39% during the dry season. Dioxin-like PCBs (DLPCBs) contributed 38% during the rainy season and 33% during the dry season. In addition, DLPCB accounted for 26% and 40% of indoor and outdoor PCB emissions, respectively. Iron and steel production were identified as the highest identified contributing sources, accounting for 76% of PCB emissions in the rainy season, while plastic combustion had the highest contribution in the dry season, accounting for 44% of PCB emissions. Incremental Lifetime Cancer Risk assessment showed ingestion as the main exposure pathway for children and adults during the two seasons (74.42% and 58.24%, respectively), followed by dermal exposure, while inhalation had the least contribution. A multifaced approach involving relevant agencies, the industry, and the community is required to reduce exposure.

Occurrence and Sources of Persistent Organic Pollutants in Upper Urban Soil of Cluj-Napoca, Romania

"Most persistent organic pollutants (POPs) were made for specific purposes due to certain characteristic and properties. They can cause various diseases and are problematic for the environment due to their high persistence and toxicity. This study attests the presence of three classes of POPs namely polycyclic aromatic hydrocarbons (PAHs), organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) in the upper urban soils of Cluj-Napoca, Romania. Soil samples were collected from 10 sampling points areas with heavy traffic. For determination of the compounds, gas chromatography coupled with mass spectrometry and with electron capture detector was used. The obtained results indicate a low level of pollution, the concentrations ranging between 8.83–184.92 ng/g for PAHs, 5.36–112.35 ng/g for PCBs, and 25.96–334.83 ng/g for OCPs. To identify the pollution emission sources, different PAHs and OCPs diagnostic ratios have been applied. Keywords: persistent organic pollutants, polycyclic aromatic hydrocarbons, polychlorinated biphenyls, organochlorine pesticides, upper urban soil"

Sources of persistent organic pollutants and their physiological effects on opportunistic urban gulls

Urbanization is associated with drastic shifts in biodiversity. While some species thrive in urban areas, the impact of inhabiting these human-altered environments on organism physiology remains understudied. We investigated how exposure to polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) affects the physiology of yellow-legged gulls (Larus michahellis) inhabiting a densely populated, industrialized city. We analyzed blood samples from 50 gulls (20 immatures and 30 adults) and assessed 27 physiological parameters and biomarkers related to xenobiotic protection, health, and feeding habits in these same individuals. We also tracked the movements of 25 gulls (15 immatures and 10 adults) to identify potential sources of persistent organic pollutants (POPs). Both adult and immature gulls primarily inhabited urban areas, followed by marine habitats. Immature gulls spent more time in freshwater, landfills, and agricultural areas. Bioaccumulated ΣPCB (median = 92.7 ng g-1 ww, 1.86–592) and ΣPBDE (median = 1.44 ng g-1 ww, 0.022–9.58) showed no significant differences between age and sex groups. Notably, immature males exhibited the highest correlations with POP concentrations, particularly with the activity of carboxylesterases (CEs), suggesting a higher sensitivity than adults. These findings highlight the potential of plasmatic CEs in immature yellow-legged gulls as effective tracers of POPs exposure and effects, offering insights into the anthropogenic impacts on urban biodiversity.

Assessment of legacy and alternative halogenated organic pollutants in outdoor dust and soil from e-waste sites in Nigeria: Concentrations, patterns, and implications for human exposure

E-waste is often processed informally, particularly in developing countries, resulting in the release of harmful chemicals into the environment. This study investigated the co-occurrence of selected persistent organic pollutants (POPs), including legacy and alternative halogenated flame retardants (10 polybrominated diphenyl ethers (PBDEs), decabromodiphenyl ethane (DBDPE), syn and anti-dechlorane plus (DP)), 32 polychlorinated biphenyls (PCBs) and 12 organochlorine pesticides (OCPs), in 20 outdoor dust and 49 soil samples from 7 e-waste sites in Nigeria. This study provides the first report on alternative flame retardants (DBDPE and DP) in Nigeria. The total concentration range of the selected classes of compounds was in the order: ∑10PBDEs (44–12300 ng/g) > DBDPE (4.9–3032 ng/g) > ∑2DP (0.7–278 ng/g) > ∑32PCBs (4.9–148 ng/g) > ∑12OCPs (1.9–25 ng/g) for dust, and DBDPE (4.9–9647 ng/g) > ∑10PBDEs (90.3–7548 ng/g) > ∑32PCBs (6.1–5025 ng/g) > ∑12OCPs (1.9–250 ng/g) > ∑2DP (2.1–142 ng/g) for soil. PBDEs were the major contributors to POP pollution at e-waste dismantling sites, while PCBs were the most significant contributors at e-waste dumpsites. DBDPE was found to be significantly associated with pollution at both e-waste dismantling and dumpsites. Estimated daily intake (EDI) via dust and soil ingestion and dermal adsorption routes ranged from 1.3 to 2.8 ng/kg bw/day and 0.2–2.9 ng/kg bw/day, respectively. In the worst-case scenario, EDI ranged from 2.9 to 10 ng/kg bw/day and 0.8–5.8 ng/kg bw/day for dust and soil, respectively. The obtained intake levels posed no non-carcinogenic risk, but could increase the incidence of cancer at some of the studied e-waste sites, with values exceeding the USEPA cancer risk lower limit (1.0 × 10−6). Overall, our results suggest that e-waste sites act as emission point sources of POPs.

Micro problems with macro consequences: accumulation of persistent organic pollutants and microplastics in human breast milk and in human milk substitutes.

Industrial activities provide a modern human lifestyle with advances and comforts in every field. However, such scenario has brought several negative issues. Persistent organic pollutants (POPs) and a growing plastic usage together with the degradation byproducts, namely microplastics (MPs), are current environmental problems present in every ecosystem, disturbing all forms of life. POPs and MPs are also found in human consumption products including animal and vegetal derivatives, human milk substitutes, and in human breast milk. To date, it is currently unknown what are the effects of MPs and POPs when ingested during the first and most important stage for health programming of the offspring, the first 1000days of life. Here, we add epidemiological and clinical evidence supporting major sources of POPs and MPs in the ecosystem; and we will precisely describe the effect of POP and MP accumulation in animal- or plant-based infant formulas and human breast milk, modulating health outcomes in the newborn. This review provides a rational to incentive the POP and MP identification in human breast milk and human milk substitutes for avoiding susceptibility to negative health outcomes for the newborn.

Distribution, Source, and Ecological Risk Assessment of Persistent Organic Pollutants in Surface Sediments of Boao Coastal Waters

Persistent organic pollutants (POPs) in the environment have the characteristics of persistence, bioaccumulation, teratogenicity, carcinogenicity, and mutagenicity. Long-term exposure of low-content POPs will also have a certain impact on marine ecosystems and human beings. The contents of three typical persistent organic pollutants[polycyclic aromatic hydrocarbons (PAHs), organochlorine pesticides (OCPs), and polycyclic biphenyls (PCBs)] of surface sediments were analyzed using gas chromatography and mass spectrometry (GC-MS) to assess the pollution characteristics of persistent organic pollutants in Boao coastal waters. The distribution and source of persistent organic pollutants were analyzed in this study, and the ecological risk was assessed using three different methods:the effect interval low/median method (ERL/ERM), mean effect interval median quotient method (M-ERM-Q), and mean potential impact concentration quotient method (M-PEC-Q). The results indicated that the contents (measured by dry weight) of ΣPAHs, ΣOCPs, and ΣPCBs in the study area were 4.5-367.50, 3.99-175.30, and ND-2.89 ng·g-1, respectively, which were at a low level, and the overall distribution showed a trend of gradually increasing toward the sea. The results of POPs source analysis showed that the PAHs in the study area were mainly from the combustion of wood and coal. Among OCPs, the HCH was mainly from lindane, the historical land-based input had been completely degraded, and the DDT was mainly the traditional DDTs pesticides, with additional continuous DDT input. The PCBs were primarily pentachlorobiphenyls, which might have come from the release of paint on the bottom of the hull in the early stage of shipping and the peeling off of paint from old ships. The ecological risk assessment results showed that there was little difference among the assessment results of the three methods, which showed that only phenanthrene monomer of PAHs in the study area had a slight negative impact, and the DDT and the γ-HCH among PAHs would cause great ecological risk, whereas PCBs and other pollutants would not cause ecological risk. On the whole, the possibility of comprehensive ecological risk caused by the three pollutants was very small.

Effect of Persistent Organic Pollutants on Human Health in South Korea: A Review of the Reported Diseases

Persistent organic pollutants (POPs) usually originate from human activities and have been released into the environment for several decades. They are highly resistant to natural decomposition and can accumulate in an organism’s tissues and in all environmental components. Due to their unique characteristics, they have an ability to bio-magnify and bio-accumulate in animals, through the food chain and via inhalation, severely endangering the health of people. As reported, the exposure of humans to POPs causes various health problems such as cancers, diabetes, birth defects, endocrine disruption, cardiovascular diseases and dysfunctional immune and reproductive systems. The residents of South Korea are likely to face a high risk of diseases because of the existence of POPs in the environment. For instance, South Korea’s atmosphere has been reported as a hotspot for POP pollution. Besides, South Koreans’ high amount of seafood consumption is considered another source of POPs. Therefore, this article reviews the status of POP contamination in food and the health impact of POPs in South Korea. Based on the findings, the most-reported diseases were obesity and diabetes, which positively correlated to age, food habits, body index, and level of exposure to POPs. In addition, cancer and metabolic diseases are at an alarming level. Therefore, the public health impacts of POPs need continuous assessment in South Korea over the next decade.

Occurrence, distribution, and ecological risk of heavy metals and persistent organic pollutants (OCPs, PCBs, and PAHs) in surface sediments of the Ashtamudi wetland, south-west coast of India

Monitoring heavy metals (HM) and persistent organic pollutants (POP) has become more important recently, as they pose serious threats to tropical aquatic ecosystems. The Ashtamudi wetland a Ramsar Site in the southwest coast of India must be monitored due to the intense urbanisation and anthropogenic activities that occur in the nearby areas of this wetland. This study aims to identify potential sources of POPs (OCPs, PCBs, and PAHs) and HM in the surface sediments of Ashtamudi wetland, as well as to assess their ecological risk. The enrichment factor (EF), contamination factor (CF), degree of contamination (CD),geo-accumulation index (Igeo), pollution load index (PLI), and sediment quality guidelines (SQG) were used as pollution indices. The average concentrations of HM were Iron (39582.52 mg/kg) > manganese (365.92 mg/kg) > Zinc (91.39 mg/kg) > nickel (49.36 mg/kg) > Copper (31.47 mg/kg) > lead (21.21 mg/kg) > Cadmium (0.73 mg/kg). The concentrations of HM detected during the study were on par with or even higher than the other coastal systems. Several areas of the Ashtamudi wetland are extremely enriched and moderately to considerably contaminated with cadmium (EF and CF indices). Nickel exceeds the ERM (Effects Range Median) in some sampling stations. The Ashtamudi wetland has not been seriously contaminated by organochlorine pesticides (2.03 to 2.45 μg/kg) and polychlorinated biphenyls (0.26 to 0.35 μg/kg). Sediments are moderately contaminated with polycyclic aromatic hydrocarbons (202.81–158.23 μg/kg) from urban emission sources of Kollam. These results can be used as a reference point for future research on organic contaminants in Indian wetlands and highlight the need for effective controls of micro pollutants.

Biomagnification and elimination effects of persistent organic pollutants in a typical wetland food web from South China

This study investigated the quantitative sources of persistent organic pollutants (POPs), their biomagnification factors, and their effect on POP biomagnification in a typical waterbird (common kingfisher, Alcedo atthis) food web in South China. The median concentrations of polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) in kingfishers were 32,500 ng/g lw and 130 ng/g lw, respectively. The congener profiles of PBDEs and PCBs showed significant temporal changes because of the restriction time points and biomagnification potential of different contaminants. The concentrations of most bioaccumulative POPs, such as CBs 138 and 180 and BDEs 153 and 154, decreased at lower rates than those of other POPs. Pelagic fish (metzia lineata) and benthic fish (common carp) were the primary prey of kingfishers, as indicated by quantitative fatty acid signature analysis (QFASA) results. Pelagic and benthic prey species were the primary sources of low and high hydrophobic contaminants for kingfishers, respectively. Biomagnification factors (BMFs) and trophic magnification factors (TMFs) had parabolic relationships with log KOW, with peak values of approximately 7. Significant negative correlations were found between the whole-body elimination rates of POPs in waterbirds and the log-transformed TMFs and BMFs, indicating that the strong metabolism of waterbirds could potentially affect POP biomagnification.

Sea spray as a secondary source of chlorinated persistent organic pollutants? - Conclusions from a comparison of seven fresh snowfall events in 2019 and 2021

Secondary sources of persistent organic pollutants (POPs) gain in importance worldwide as primary sources decline. In this work, we aim to determine whether sea spray may be a secondary source of chlorinated POPs to the terrestrial Arctic, since a similar mechanism was proposed there only for the more water-soluble POPs. To this end, we have determined polychlorinated biphenyls and organochlorine pesticides concentrations in fresh snow and seawater collected in the vicinity of the Polish Polar Station in Hornsund in two sampling periods covering spring 2019 and 2021. To support our interpretations, we include also metal and metalloid, and stable hydrogen and oxygen isotopes analysis in those samples. A significant correlation was found between the concentrations of POPs and the distance from the sea at the sampling point, yet the confirmation of sea spray impact lies more in capturing an event with negligible long-range transport influence where the detected chlorinated POPs (Cl-POPs) matched in composition the compounds enriched in the sea surface microlayer, which is both a source of sea spray and a seawater microenvironment rich in hydrophobic substances.

Effects of persistent organic pollutants on environment, health and mountains: a review

Persistent organic pollutants (POPs) are chemicals that persist in the environment, bioaccumulate through the food chain and can exhibit toxicity with threatening effects to the environment, humans and animals. Due to their volatility and semi-volatility, they are found in air and they have the potential to be transported to high-altitude mountain locations as well as to high-latitude areas. The objectives of this study are; firstly, to look into the environmental and health impacts of POPs; secondly, to look into studies that covered the transport of POPs through atmospheric air, water and other POP sources such as sediments and soils; and, thirdly, to look into possible solutions that have been put forward regarding POP removal from the environment. The methodology that was used to look for references was through the Google, PubMed, Google Scholar and ResearchGate. The initial search retrieved 63 peer-reviewed articles and abstracts. The studies revealed that, POPs remain in the environment, causing health effects through their toxicity. Humans and animals take in POPs through the food chain because of the lipophilic nature of these compounds. Solutions that have been put forward by the studies are stopping the use of POPs, substituting POPs with non-toxic chemical compounds and having a wide range of non-chemical alternatives.

Source identification of PCBs in Antarctic air by compound-specific isotope analysis of chlorine (CSIA-Cl) using HRGC/HRMS

Occurrence of persistent organic pollutants (POPs) in the Polar Regions has received great concern in the past several decades due to their long-term adverse effect on biological health in such a fragile environment. However, there is still argument over their source and fate in these pristine areas. Here we attempted to use a novel approach (compound-specific isotope analysis of chlorine, CSIA-Cl) to identify the source of POPs in Antarctic air by comparison with the source area. The results showed that the relative isotope-ratio variation of Cl (δ37Cl′) values showed a large variation from − 137 to 9.04 ‰ in the gas-phase samples, and a significantly negative correlation (p < 0.01) was obtained against the logKoa values of PCBs. There were no significant correlations (p > 0.05) observed between the δ37Cl′ values and meteorological parameters except for PCB-28 which showed temperature dependence. By contrast, the δ37Cl′ values in the urban (Beijing) air ranged from − 12.8 to 2.03 ‰. The larger variation of δ37Cl′ in Antarctic air indicated evidently influence of long-range atmospheric transport (LRAT) on isotopologue fractionation of PCBs. This study may shed light on the application of CSIA-Cl for source identification of chlorinated POPs on a large scale.

Mapping the Contribution of Biomass Burning to Persistent Organic Pollutants in the Air of the Indo-China Peninsula Based on a Passive Air Monitoring Network.

Biomass burning (BB) is an important source of atmospheric persistent organic pollutants (POPs) across the world. However, there are few field-based regional studies regarding the POPs released from BB. Due to the current limitations of emission factors and satellites, the contribution of BB to airborne POPs is still not well understood. In this study, with the simultaneous monitoring of BB biomarkers and POPs based on polyurethane foam-based passive air sampling technique, we mapped the contribution of BB to polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) in the Indo-China Peninsula. Spearman correlations between levoglucosan and 16 PCBs (rs = 0.264-0.767, p < 0.05) and 2 OCPs (rs = 0.250-0.328, p < 0.05) confirmed that BB may facilitate POP emissions. Source apportionment indicated that BB contributed 9.3% to the total PCB and OCP mass. The high contribution of positive matrix factorization-resolved BB to PCBs and OCPs was almost consistent with their concentration distributions in the open BB season but not completely consistent with those in the pre-monsoon and/or monsoon seasons. Their contribution distributions may reflect the use history and geographic distribution in secondary sources of POPs. The field-based contribution dataset of BB to POPs is significant in improving regional BB emission inventories and model prediction.

A comprehensive assessment, source input determination and distribution of persistent organic pollutants (POPs) along with heavy metals (HMs) in reservoir lake sediments from Çanakkale province, Türkiye.

This study presents the distribution of persistent organic pollutants (POPs), polycyclic aromatic hydrocarbons (PAHs) and heavy metals (HMs) in the sediments from four dams and two ponds in the Çanakkale city, Türkiye. The total concentration varied from 41.47 to 145.45ng/g d.w. for PAHs; 1.40-14.96ng/g d.w. for organochlorine pesticides (OCPs) and 0.13-3.31ng/g d.w. for polychlorinated biphenyls (PCBs). The total polychlorinated dibenzo-p-dioxins/furans (∑PCDD/Fs) concentrations varied between 7.35 and 63.46pg/g d.w. The HM distribution in sediments ranged from 9.41 to 21.13mg/kg d.w. for As; 0.20-0.39mg/kg d.w. for Cd; 19.4-281.68mg/kg d.w. for Cr; 23.50-118.25mg/kg d.w. for Pb and 118.9-374.82mg/kg d.w. for Zn. This paper also elucidates possible sources of POP and HMs in sediment by using diagnostic ratios. The calculated ratios were shown that anthropogenic input is the source of these pollutants in sediments. Principal component analysis showed that the low molecular weight of POPs is considerably related and correlated, while high molecular weight pollutants have made another group and highly correlated with each other. The results indicated that anthropogenic pollution is mainly related to atmospheric input. Anthropogenic pollutants are more apparent at Atikhisar and Bakacak dams close to urbanized locations. Rather than the anthropogenic impact, based on the measured data interpretation, the global climate change effect was seen in Bakacak dam. The overall concentration of all pollutants revealed that Atikhisar and Bakacak sediments are high-level polluted areas according to several types of sediment guidelines.

Gaseous and soil OCPs and PCBs along the Indus River, Pakistan: spatial patterns and air-soil gradients.

This study presents first-hand information on the occurrence of persistent organic pollutants (POPs) in the ambient air and surface soil along the Indus flood-plain, Pakistan. The sampling campaign was conducted at 15 site locations during 2014-15, along the Indus River (approximately 1300 km). Composite surface soil samples (N = 15) and passive air samples (N = 15) were collected for the estimation of gaseous POPs as well as air-soil exchange to evaluate the POP emission and distribution or dispersion patterns, source tracking, and contribution of the local and regional sources towards POP accumulation in the Indus River system. Among the studied POPs, levels of DDTs and PCBs were noticeably higher in ambient air (50-560 and 10-1100 pg m-3) and in soil (0.20-350 and 1.40-20 ng g-1), respectively. Regarding the spatial patterns, higher DDT concentrations (ng g-1) were detected in the air and soil samples collected from the wet mountain zone (WMZ) (p < 0.05), followed by the alluvial riverine zone (ARZ), low-lying mountain zone (LLZ), and frozen mountain zone (FMZ). The PCB data did not exhibit significant differences (p > 0.05) for the air samples, while PCB concentrations were significantly higher (p < 0.05) in soil from the LLZ, which may be associated with rapid urbanization and industrial activities in this area. The air-soil exchange of DDTs and PCBs showed net volatilization at most of the studied sites except for a few samples from the FMZ and WMZ. Results of this study about air-soil exchange gradients indicate the long range regional atmospheric transport (LRAT) of POPs to the colder areas (FMZ) of Pakistan, where these act as a secondary source of POPs in these areas.

Atmospheric deposition contributed mostly to organophosphorus flame retardant entering into the Bohai Sea, China

Atmospheric emission sources of persistent organic pollutants (POPs) in China's eastern seaboard regions cause heavy POP contamination in the Bohai Sea (BS), China. Because many rivers are emptying into the BS, terrestrial runoff has been considered a dominant pathway of POPs onto the BS. Here, we explored the contribution of atmospheric transport and terrestrial runoff to organophosphorus flame retardants (OPFRs) to the BS by using an atmospheric transport model and a terrestrial runoff model. We examined the sensitivity and response of OPFR in the BS seawater to its atmospheric transport, deposition, and riverine discharge via terrestrial runoff. Both terrestrial runoff and atmospheric transport model simulations reveal that the atmospheric transport and deposition, including dry, wet, and diffusive gaseous deposition, dominate OPFR input into the BS. The total OPFR fluxes entering the BS via the atmospheric pathway and riverine input were 70.4 and 2.8t/yr in 2013, respectively.

Functional Silane-Based Nanohybrid Materials for the Development of Hydrophobic and Water-Based Stain Resistant Cotton Fabrics Coatings.

The textile-finishing industry, is one of the main sources of persistent organic pollutants in water; in this regard, it is necessary to develop and employ new sustainable approaches for fabric finishing and treatment. This research study shows the development of an efficient and eco-friendly procedure to form highly hydrophobic surfaces on cotton fabrics using different modified silica sols. In particular, the formation of highly hydrophobic surfaces on cotton fabrics was studied by using a two-step treatment procedure, i.e., first applying a hybrid silica sol obtained by hydrolysis and subsequent condensation of (3-Glycidyloxypropyl)trimethoxy silane with different alkyl(trialkoxy)silane under acid conditions, and then applying hydrolyzed hexadecyltrimethoxysilane on the treated fabrics to further improve the fabrics’ hydrophobicity. The treated cotton fabrics showed excellent water repellency with a water contact angle above 150° under optimum treatment conditions. The cooperative action of rough surface structure due to the silica sol nanoparticles and the low surface energy caused by long-chain alkyl(trialkoxy)silane in the nanocomposite coating, combined with the expected roughness on microscale due to the fabrics and fiber structure, provided the treated cotton fabrics with excellent, almost super, hydrophobicity and water-based stain resistance in an eco-sustainable way.