Average Total Concentration Research Articles

International pellet watch; origins and monitoring of oil markers in surface sediments and plastic resin pellets in southern Caspian Sea, Iran.

Oil pollution in marine environments, particularly along the southern coasts of the Caspian Sea, has become a serious issue due to anthropogenic activities such as shipping, tourism, fishing, and urban development. This study aimed to assess the concentration and origin of PAHs, n-alkanes, hopanes, and steranes in sediment samples (coastal area and coastal line) and resin pellets collected from 30 stations along the southern shores of the Caspian Sea (Golestan, Mazandaran, and Gilan provinces). The results showed that PAHs concentrationranged from 530.4 to 9201ng/g-dw in coastal area sediments, 753 to 10,528ng/g-dw in coastal line sediments, and 5920.7 to 16,548ng/g-pellet in resin pellets. The average total concentration of alkanes ranged from 251 to 7059μg/g-dw in coastal area sediments, 273 to 8401.6μg/g-dw in coastal line sediments, and 1967 to 22,258μg/g-pellet in resin pellets. The total terpene concentration in coastal area sediments was 60.5 to 537.5ng/g-dw, in coastal line sediments 120.6 to 811.3ng/g-dw, and in resin pellets 227 to 2886.5ng/g-pellet. Additionally, the highest concentrationwere observed in port-related areas (Bandar Anzali, Amirabad, and Astara), while the lowest concentrationwere found in recreational areas. Resin pellets generally exhibited higher concentrationof all investigated compounds compared to sediments. The classification of PAH pollution intensity based on global criteria indicated moderate to very high contamination in sediments and high to very high contamination in resin pellets. The determination of pollution levels based on the concentration of n-alkanes in southern Caspian Sea sediments revealed very high and considerable pollution. The categorization of hopane compounds' pollution intensity in resin pellets, according to International Pellet Watch classification, indicated a lack of pollution in all samples. The primary source of all compounds was identified as petrogenic.

Potentially harmful elements in mining sites in Ghana: assessment of their carcinogenic and non-carcinogenic health risks for children and adults

PurposePotentially harmful elements (PHEs) in the soil at gold mining sites can endanger the health and sustainability of the local community. We examined the potential health risks associated with the presence of PHEs (Al, Cd, Cu, Fe, Hg, Mn, Pb, Sb, Se and Ti) in the soils of active, closed/abandoned/former and profile gold mine sites in Ghana.Design/methodology/approachWe collected 102 soil samples from these mine sites, analysed them for their total element contents and calculated the geo-accumulation index, enrichment factor, contamination factor and pollution load index (PLI) (Igeo). We calculated the risks to human health by utilizing the hazard index (HI) and hazard quotient (HQ) for adult males, adult females and children who may ingest contaminated soil particles.FindingsThe average total Cd concentration in the soils was above the global average of 0.2 mg/kg for abandoned (2.86 mg/kg), active (3.93 mg/kg) and profile (4.04 mg/kg) areas. Mercury was detected at elevated concentrations in the soil of active mines (0.92 mg/kg), profiles (0.89 mg/kg) and abandoned mines (0.87 mg/kg). In the active, abandoned and profile soils, titanium concentrations were 14.18, 6.74 and 4.82 mg/kg, respectively, in several folds above the global average of 0.57 mg/kg. The majority of the sites were contaminated with Cd, Hg and Ti based on the calculated PLI values (active = 2.04, abandoned = 1.77 and profile = 2.7). Cadmium, mercury, lead and titanium in mine spoils were found to be correlated with aluminium, iron, manganese, pH, total carbon, clay content and phosphorus in a multivariate analysis using correlation and principal component analysis.Research limitations/implicationsBoth natural and anthropogenic processes contributed to the elevated metal contents in the mining sites, as indicated by the investigation’s results. The children’s hazard index values exceeded the threshold of 1.0, indicating the presence of non-carcinogenic risks.Practical implicationsGreen space technology (e.g. revegetation) may thus be critical for preserving public health and reviving the ecological integrity of the contaminated sites.Originality/valueThis study highlights health risks to local communities in southwest Ghana by investigating the presence of potentially harmful elements in soils from gold mining sites for the first time. It assesses non-carcinogenic and carcinogenic health risks using a methodology recommended by the US Environmental Protection Agency for soil-to-human health risk assessment, especially for children. The study highlights how contamination has been found, making green space technology essential for preserving ecological integrity and protecting public health. The inclusion of geospatial distribution mapping of PTEs offers a visual depiction of the spread of contamination at both active and closed mining sites.

Occurrence, spatial distribution, source apportionment, and risk assessment of antibiotics in Yangtze river surface water

The identification and source tracing of antibiotic contaminants in rivers has become a research hotspot. In this study, surface water samples were collected from 67 locations in the Yangtze River Basin, China. The detection rate, concentration, and distribution characteristics of various antibiotics in these water samples were analyzed. Based on these data, the sources of these antibiotics were traced and correlated with factors such as urban population size, industrial activity, and wastewater treatment efficiency within the sampling area. A total of 57 antibiotics were detected in the Yangtze River, with detection rates of roxithromycin, 1,7-dimethylxanthine (1,7-DTX), and florfenicol (FF) exceeding 80 %. The average total concentration of antibiotics was significantly higher in upstream regions (525.4 ng/L) compared with middle regions (89.5 ng/L) and downstream regions (246.6 ng/L). Furthermore, antibiotic concentrations positively correlated with population density and economic development (R = 0.857, p < 0.05). Based on ecological risk assessment and priority indexes, enoxacin, roxithromycin, sarafloxacin, and clarithromycin (CLR) posed medium risks. This research provides scientific guidance for the periodic monitoring and regulation of antibiotic contaminants in river ecosystems.

Occurrence, spatiotemporal distribution, and health risk of antibiotics in the Wuhan section of the Yangtze River, China.

The occurrence, spatiotemporal changes, and health hazard of antibiotics in source water and finished water in the Wuhan section of the Yangtze River are not well understood. In this study, 43 source water and finished water samples were collected from 11 water plants in Wuhan in August 2021 and May 2022. Fifty-one antibiotics from eight categories were measured. A total of 41 antibiotics were detected in the source water samples, and 24 in the finished water samples. The total antibiotic concentration in source water ranged from 1.68 to 437.18 ng/L, which is significantly higher than that in finished water (2.04-87.25 ng/L). Sulfonamides and lincosamides were predominant, accounting for nearly 80% of the total antibiotic concentration. Lincomycin constituted nearly 30% of the total antibiotic concentration in the source water. In August 2021, the average total antibiotic concentration in source water was 107.12 ng/L, higher than in May 2022 (63.13 ng/L). Spatially, the total antibiotic concentrations in samples collected from the Han River, a tributary of the Yangtze River, were higher than those in the main stream of the Yangtze River. Ecological risk assessment indicated that the hazard posed by most antibiotics were negligible. Lincomycin potentially posed a high health hazard, and clarithromycin and roxithromycin posed a moderate hazard to infants.

Source identification and human health risk to polychlorinated biphenyls in public parks and playground surface soils, southern zone of Ghana.

Polychlorinated biphenyls (PCBs) constitute a typical example of persistent organic pollutants (POPs) that have been detected globally in most environmental media. Soil serves as a critical reservoir for PCBs. This research is aimed at evaluating the potential exposure and associated health risks posed by soil-laden PCBs to humans during outdoor activities on public playgrounds and parks within the southern zone of Ghana where limited studies have been undertaken. Surface soils collected from 56 sites were processed and analyzed for seven indicator PCBs in soil particle sizes less than 63µm. A multi-residual analytical approach for the simultaneous analysis of PCBs and polycyclic aromatic hydrocarbons (PAHs) via gas chromatography tandem mass spectrometry was utilized. The results indicated that the concentration of PCBs ranged from 0.26 to 24.00µg/kg with an average total concentration of 1.86 ± 3.23µg/kg which is below the environment guideline threshold of 1.3mg/kg stipulated by the Canadian Council of Ministers for residential playgrounds/parkland soils. Multivariate analysis showed that the sources of the PCBs could be attributed predominantly to historical release, atmospheric transfer, and deposition. The excess lifetime cancer risks posed to children and adults are less than 10-6 thereby implying the existence of low carcinogenic health risk to the human populace within the southern zone of Ghana. Thus, the conduct of outdoor activities at the public playgrounds/parks within these highly populated areas poses no significant risk to human health.

Influence of local meteorology and gaseous pollutant emissions on atmospheric nanoparticle concentrations in a pedestrian way in urban region

The roadside environment is one of the major sources of nanoparticle emission in the urban regions. The complex mixture of different pollutants makes it hard to understand the dynamics and behavior of nanoparticles. The study aims to analyze the dynamics of atmospheric nanoparticles ranging from 10 to 1000 nm along with local meteorological conditions and gaseous pollutants in a pedestrian way at a busy street in Delhi, a megalopolis in India, during all five major seasons of the study area. Nucleation mode particles were higher during the spring season, whereas the contribution of Aitken mode particles dominated the total particle number concentrations in the rest of the seasons. Due to the influence of vehicular sources, rush hour concentrations were higher than during non-rush hours. Thus, the diurnal pattern in particle concentration strongly coincided with emissions associated with the vehicular flow. During the winter season, the average total particle number concentration was observed to be maximum (4.1 × 104 cm−3) with a higher surface area of particles of 3.5 × 10−3 mm2 m−3. Compared to the monsoon season, the concentration of NOX was 5 times higher in winter. The boundary layer height in the study region ranged from 600 to 2400 m during different seasons, and the maximum ventilation coefficient was observed to be > 3000 m2s-1 during summer. Precipitation reduced the concentration of particles by half, from 2.2 x 104 to 1.1 x 104 cm−3, due to wet scavenging. The study revealed that the concentrations of particles depend not only on primary emissions but also are influenced by local meteorology and other co-emitted pollutants. Understanding the dynamics of atmospheric nanoparticles in urban roadside environments as outlined in this study is crucial to devise necessary mitigation measures for people residing near the road in order to reduce health impact and improve air quality.

Residues of neonicotinoid insecticides in artificial waterways of the Eastern Route of the South-to North water diversion project, China: Implications for environmental risks and human health

Neonicotinoids (NEOs) are ubiquitous in global surface waters. However, the occurrence of NEOs in artificial waterways is unclear. The South-to-North Water Diversion Project (SNWDP) is the largest water diversion project in the world. Water samples from the Luoma Lake to Dongping Lake section of the Eastern Route (ER)-SNWDP were collected and analyzed for eight widely used NEOs to study their spatiotemporal distribution, ecological risks, and health risks. The total NEO concentration was 9–666, 34–138, 8–126, and 7–103 ng L−1 in the water diversion channel, Luoma Lake, Nansi Lake, and Dongping Lake, respectively. The average total NEO concentration in the water diversion channel in the dry season was twice as high as it was in the wet season, due to the precipitation dilution effect. Rather than Luoma Lake, Nansi Lake and Dongping Lake showed a seasonal difference in the average total NEO concentration. NEO concentrations in the three lakes were influenced by the inputs from natural rivers and the water diversion channels under artificial regulation. The seasonal variation in NEO composition between the water diversion channel and the three lakes suggested the channel water was not the only source for NEOs in lakes. For individual NEO ecological risks, thiamethoxam, clothianidin, and imidacloprid in the two seasons would result in high chronic risks in the water diversion channel, and moderate to high risks in Nansi Lake and Luoma Lake. Thiacloprid would result in high chronic risks in Dongping Lake in the two seasons and Luoma Lake in the wet season. For the integral NEO risks, none of the lake water sites exceeded the acute ecological threshold. Health risk assessment suggested drinking water obtained from the ER-SNWDP was safe for public health. The health risks for children exposed to NEOs from the water intake and dermal intake were higher than that for adults.

Mapping soil VOCs using three green sample extraction techniques and GC–MS

Sample preparation is a very crucial step prior to sample analysis. Three green adsorptive sample preparation micro-extraction techniques were investigated (smart solid-phase microextraction (SPME), high-capacity sorptive extraction (HiSorb), and stir bar sorptive extraction (SBSE)) for the determination of volatile organic compounds (VOCs) emitted from vineyard soil samples after method optimization. More specifically, the 95 μm Carbon Wide Range/Polydimethylsiloxane (CWR/PDMS) smart SPME fiber, CWR/PDMS HiSorb, and PDMS Twister micro-extraction tools were compared for their extraction capabilities. The headspace (HS)-SPME-gas chromatography-mass spectrometry (GC–MS) method was proved better for the extraction of VOCs from the vineyard soils due to shorter exposure time (45 min), its automation (use of a fully automated system compared to the other two), and the high sample throughput analysis. The validation of the HS-SPME-GC–MS method showed good linearity (R2 ≥ 0.9951) and limit of detection (LOD), whereas the limit of quantitation (LOQ) ranged from 0.04-3.65 μg/kg. Also, the repeatability and reproducibility of the results showed a relative standard deviation (RSD) lower than 4.73 %. A total number of 47 soil-derived VOCs were identified through the validated HS-SPME-GC–MS method, and 9 targeted VOCs were quantified with total average concentrations ranging from 0.14-28.07 µg/kg. Smart SPME fiber proved beneficial over the two other tools, highlighting the aspects of green chemistry.

Characterization and source apportionment of ambient VOC concentrations: Assessing ozone formation potential in the Barnett shale oil and gas region

Atmospheric concentration and distribution of volatile organic compounds (VOC) are influenced by localized emissions and the fate and transport of secondary products formed through photochemical reactions. This study identifies the sources of VOC and its contribution to ozone formation in the Barnett Shale region, specifically in Denton, Texas, during the ozone seasons of 2015 through 2022. A total of 31 critical ozone precursor VOC compounds were observed at this site with an average total VOC concentration of 146 ppb-C, with n-alkanes from extensive oil and gas activities in the area contributing to 96.64% of the total VOC. Source apportionment using dispersion normalized positive matrix factorization (DN-PMF) identified eight VOC sources, with natural gas emissions (72%) being the dominant source followed by a combined source of natural gas combustion and aviation emissions (8.3%). Ozone formation potential (OFP) by VOC species was calculated using the propylene-equivalent concentration (propy-equiv) method. OFP calculated for all the apportioned sources highlighted that natural gas sources contributed significantly to the ozone formation in this region besides isoprene from biogenic sources and reactive alkenes from urban and industrial activities. This study underscores the critical role of slow-reacting n-alkanes along with other highly reactive VOC from urban and industrial sources influencing ambient air quality and it identifies strategies for mitigating ground-level ozone in urban areas affected by oil and gas extraction and production.

An assessment of the environmental radiation risk from the petrologic units of north-eastern Nigeria; an insight from aero-radiometric data interpretation

Information regarding the radiation risk posed by radioactive emissions from the petrologic units in North eastern Nigeria is extremely limited. Consequently, there has been little research conducted on the environmental impact of radiation exposure from different petrologic units in this region. Hence, the 13 petrologic components of the area that comprises of the migmatites-gneiss (MG), banded gneiss (BG), biotite-hornblende granites (OGe), porphyritic biotite-hornblende granites (OGp), charnockytes (Ch), ignimbrites (JYG), basalts (bb), Keri-Keri Formation (KK), Gombe Sandstones (GS), Pindiga Formation (PS), Yolde Formation (YL), Bima Sandstones (BS), and alluvium (AL) deposits were assessed using aero-radiometric data (equivalent uranium, equivalent thorium, and percentage potassium radio-elements) acquired by Nigerian geological survey agency (NGSA) in 2009. The objective of this study is to compute the amount of radiation across the various rock units of the study area, and examine their radiation risk parameters. The results of this study showed variable levels of radiation across the various rock units examined. The average total activity concentration values recorded ranges from 261.67 ± 447.12 Bq/Kg across KK rock unit to 1482.02 ± 447.12 Bq/Kg across OGp/OGe rock types of the study area. Moreover, the average radium equivalent (Rn eq), absorbed dose rates (D) estimated ranges from 113.83±461.33 Bq/Kg to 305.19 ± 58.51 Bq/Kg, and 51.88 ± 29.65 nGyh−1 to 144.94 ± 29.65 nGyh−1 along KK Formation, OGp, and same KK Formation, and OGp respectively. The average environmental radiation hazard parameters of the annual effective dose rate (AEDE), activity utilization index (AUI), respiratory dysfunction parameters (RH in, RH out), annual gonad dose equivalent (AGDE), and excess life cancer risk (ELCR) measured across all rock units were found to be within or above their respective acceptable limits of 1 mSv/y, 300 μSv/y, and 0.29 × 10−3. Additionally, based on the conspicuously higher hazardous radiation (D, Rn eq, AEDE AGDE, RH in, RH out, and ELCR) emissions estimated from the OGp, OGe, MG, BG, and Ch petrologic units, the inhabitants of these localities should therefore limit themselves from excessive exposure to these rocks. Therefore, periodic monitoring of these areas is recommended.

ВЫНОС МИКРОЭЛЕМЕНТОВ ФУМАРОЛАМИ АВАЧИНСКОГО ВУЛКАНА (КАМЧАТКА)

The trace element composition of high-temperature gases of Avachinsky volcano was investigated. For that purpose 25 samples of gas condensates and sublimates deposited in four quartz tubes were analyzed. The total average concentration of trace elements (excluding S, Cl, F, Si) in the condensates was 87 mg/l, the maximum 210 mg/l, among which B, K, Na, Br, As predominated. A large number of samples taken over a period 2013–2023 allowed us to evaluate the variations of element concentrations, their dependence on fumarole temperature and the season of sampling. The enrichment factors normalized for magnesium, made it possible to determine the elements transported in the plume in the form of volatile compounds (S, Cl, Te, I, B, Br, Cd, As, F, Re, Se, Bi, Tl, Hg, Sn, Sb, Pb, etc.) and in the form of silicate aerosol (Ti, Fe, Ga, Al, Ca, Mn, REE et al.). The ore element emission by Avachinsky volcano is comparable to that of Mutnovsky volcano (Kamchatka) and significantly lower than the emission by volcanoes in the stage of stationary degassing, such as Kudryavy and Pallas Peak (Kuril Islands), which can be explained by higher concentrations of HCl in the gases of the latter.

Source-risk and uncertainty assessment of trace metals in surface sediments of a human-dominated seaward catchment in eastern China

Current total concentration-based methods for source attribution and risk assessment often overestimate metal risks, thereby impeding the formulation of effective risk management strategies. This study aims to develop a framework for source-specific risk assessment based on metal bioavailability in surface river sediments from a human-dominated seaward catchment in eastern China. Metal bioavailability was quantified using chemical fractionation results, and source apportionment was conducted using the positive matrix factorization (PMF) model. Risk assessment integrated these findings using two indices: the Potential Ecological Risk Index (PERI) and the Mean Probable Effect Concentration Quotient (mPEC-Q), with uncertainty addressed via Monte Carlo simulations. Results indicated that average total concentrations of Cu, Pb, Zn, Cr, Hg, Cd, and As exceeded their respective background levels by 1.63 to 15.00 times. The residual fraction constituted the majority, accounting for 53.84 % to 77.79 % of total concentrations, suggesting significant natural origins. However, source apportionment revealed a predominant contribution from anthropogenic activities, including industrial smelting, agricultural practices, and atmospheric deposition. The contributions were found to vary between 5.35 % and 40.03 % when the total concentration was adjusted to bioavailable content. Total concentration-based PERI/mPEC-Q assessments indicated high/moderate risk levels, decreasing to considerable/low risk levels with bioavailability adjustment. Hg and Cd were identified as priority metals. Further incorporating source appointment parameters into the risk assessment, industrial smelting was identified as the primary contributor, accounting for 66.06 % of total risk by total concentration and 65.63 % by bioavailability. This underscores the role of bioavailability in mitigating risk overestimation. Monte Carlo simulations validated industrial smelting as a major risk contributor. This study emphasizes the importance of considering bioavailability in the source-risk assessment of sediment-metals, crucial for targeted risk management in urbanized catchment areas.

Safety, efficacy, and pharmacokinetics of oral testosterone undecanoate in males with hypogonadism.

Testosterone deficiency results from insufficient testosterone production. Testosterone therapy may require dose titration to reach eugonadal serum testosterone concentrations. The primary objective was the efficacy of oral testosterone undecanoate (TLANDO; Antares Pharma Inc.) in male patients with documented hypogonadism. Secondary objectives included a comparison of oral testosterone undecanoate safety and quality-of-life assessments to 1.62% topical testosterone gel (AndroGel 1.62%; AbbVie). In this phase 3 study, 315 patients were randomized 2:1 to oral testosterone undecanoate or 1.62% topical testosterone gel (NCT02081300). Patients received 225mg oral testosterone undecanoate twice daily, and doses were adjusted by 75mg/dose at weeks 4 and 8 based on average serum total testosterone concentration and maximum observed serum concentration. The primary endpoint was the proportion of patients receiving oral testosterone undecanoate with serum total testosterone concentration within the eugonadal reference range (300-1140ng/dL). Secondary endpoints included the proportion of patients with maximum serum total testosterone concentrations within predetermined limits, safety parameters, and quality-of-life endpoints including the Short Form-36v2 Health Survey, Psychosexual Daily Questionnaire, and International Prostate Symptom Score. Overall mean±SD baseline testosterone was 205.7±71.6ng/dL. For patients receiving oral testosterone undecanoate, 87.4% demonstrated a 24-h average serum total testosterone concentration within the reference range following titration. Oral testosterone undecanoate demonstrated a nominal statistically significantly greater mean change from baseline than 1.62% topical testosterone gel for Short Form-36v2 Health Survey measures of mental health (2.91vs. -0.10; p=0.035), and mental component summary (3.82vs. 0.55; p=0.009); and Psychosexual Daily Questionnaire measure of weekly negative mood (-0.57vs. -0.20; p=0.021). Safety endpoints were comparable between therapies. No deaths or treatment-related serious adverse events were reported. Male patients with hypogonadism receiving oral testosterone undecanoate 225mg twice daily demonstrated improvements in libido and sexual frequency. Serum testosterone concentrations were within the reference range in 87% of patients without dose titration.

The Emission Characteristics of VOCs and Environmental Health Risk Assessment in the Plywood Manufacturing Industry: A Case Study in Shandong Province

The current emission characteristics of volatile organic compounds (VOCs) in the plywood manufacturing industry are not yet clearly understood, and their impact on occupational health warrants attention. This study examines VOC concentrations in adhesive-coating and hot-pressing workshops, aiming to discern the emission characteristics and evaluate the health risks to workers. The calculated VOC emission factors range from 1.5 to 3.6 g/m3 for plywood, and an average total VOC concentration of 954.17 μg/m3 is observed. Hot pressing (336.63 μg/m3) and adhesive coating (276.24 μg/m3) substantially contribute to organized and unorganized emissions, respectively. Oxygenated VOCs (OVOCs) (50.79%) predominate, followed by alkanes (16.22%) and halohydrocarbons (15.81%). Formaldehyde, acetone, and acetaldehyde are most prevalent in organized emissions, while dichloromethane, formaldehyde, and methyl methacrylate are dominant in unorganized emissions. Ozone formation potential (OFP) values range from 905.04 to 1822.35 μg/m3, with notable contributions from formaldehyde, methyl methacrylate, and acetaldehyde. Health risk assessments using the total lifetime cancer risk (T-LCR) values suggest potential cancer risks for identified VOCs, particularly formaldehyde in the hot-pressing process. These findings will contribute valuable insights for regional-scale VOC pollution control and offer guidance for minimizing environmental impact and improving occupational health and safety within the plywood manufacturing industry.

Assessing heavy metal contamination and health risks in playground dust near cement factory: exposure levels in children

Heavy metals pose significant threats to human health, particularly children. This study aimed to assess heavy metal pollution in children's playgrounds using surface dust as an indicator and to ascertain the associated exposure levels and health risks. A total of one hundred twenty dust samples were collected from the surface of playground toys in areas surrounding the cement factory in Bursa, Türkiye, on precipitation-free days. The heavy metal content of the samples was analyzed using ICP-MS. The average total concentration of heavy metals ranged from 2401 to 6832 mg/kg across the sampling sites, with the highest values observed at PG4, PG3, PG2, and PG1, respectively. The most commonly detected heavy metals in the samples included Cr, Mn, Fe, Co, Cu, Zn, Pb, Cd, As, and Ni. Statistical analysis revealed significant positive correlations (p < 0.01) among Cr, Mn, Fe, Co, Cu, Pb, As, and Ni, with Cu and Pb also showing correlation (p < 0.05). PCA analysis identified three principal components explaining 79.905% of the total variance. The Hazard Quotient (HQ) and Hazard Index values for heavy metals were found to be below the safe threshold (HQ < 1). Quantitative techniques such as the geoaccumulation index and enrichment factor are used to determine pollution levels at the sampling sites. Overall, the results indicate that cement factories significantly contribute to heavy metal pollution, with observed values varying based on proximity to the emission source.

Neonicotinoid insecticides in waters of Hongze lake, the largest impounded lake on the South-to-North water diversion project, China: Implications for environmental and public health

Contamination by neonicotinoid (NEO) insecticides in surface waters is a global problem. Nevertheless, the occurrence of NEOs in lakes is not well known. Hongze Lake, the largest impounded lake on the Eastern Route of the South-to-North Water Diversion Project, was selected to investigate the distribution, ecological risks, and health risks of NEOs. Water samples from the lake and nearby rivers were collected and analyzed for 8 widely used NEOs in three seasons. The results indicated the average total NEO concentration in summer, winter, and spring was 222, 211, and 244 ng L−1 for the river water, and 265, 213, and 181 ng L−1 for the lake water, respectively, with no statistical seasonal difference. For the river water, the highest total NEO concentration in the three seasons was observed in the Andong River. For the lake water, the total NEO concentrations in summer were relatively high in sites near the inflow river estuaries due to the high riverine inputs during the flood period. The spatial difference in NEO concentration was relatively low in winter, which may be related to the wind-driven lake current. The seasonal variation in NEO compositions in the lake was generally similar to that in the river, indicating riverine input was the important source for the lake. Huai River was the largest contributor to the NEO inputs to the lake, and Sanhe Gate was the major output pathway. Clothianidin and imidacloprid in the river and lake water would produce moderate acute ecological risks in summer. Thus, the usage of the above two NEOs should be decreased or restricted. For integral NEO risks, 53% and 58% of the river and lake water sites exceeded the acute ecological threshold, respectively. Health risk assessment suggested drinking the water obtained from the lake would not produce a negative impact on public health.

Enhancement of per- and Polyfluoroalkyl Substances (PFAS) quantification on surface waters from marinas in the douro river, Portugal

PFAS, known as "forever" compounds, are prevalent in various environments, including soils and aquatic systems, due to extensive usage. Surface waters in several European countries, especially marinas and ports with high boat traffic, require further study as potential contamination sources. Reliable methods for the extraction and quantification of these emergent compounds are essential. This study aimed to improve an existent solid phase extraction method to analyse marinas and ports’ surface waters with variable salinities (2, 9 and 17 PSU). The objectives were to: 1) optimise the solid phase extraction method, considering matrix salinity effects and cross-contaminations, 2) validate the extraction and quantification method of 18 EPA 537.1 PFAS in estuarine surface waters, using the Ultra-High Performance Liquid Chromatography – Quadrupole Time – Of – Flight – Tandem Mass spectrometry, and 3) apply the optimised method for PFAS quantification in three Portuguese marinas. All ICH criteria were successfully validated considering 9 PSU. Limits of quantification ranged from 117.80 ng/L to 385 ng/L, except for PFHpA (645.85 ng/L). PFAS levels (PFOA, HFPO-DA, PFBS, PFHxS and PFOS) were relatively low, reaching a maximum of 0.32 ng/L only for the PFOA. In Freixo marina, total average concentrations were slightly higher (∑PFAS = 1.02 ng/L) when compared to the ones found in Cais da Ribeira Port (∑PFAS = 0.94 ng/L) and Afurada marina (∑PFAS = 0.81 ng/L). PFOS concentrations are below the limit values set by the Environmental Quality Standards (36000 ng/L of PFOS for inland surface water, respectively), similar to other Portuguese river studies. This study enabled the development of a precise and reliable extraction and quantification method to quantify PFAS in estuarine surface waters, particularly from marinas. This method can be readily applied to analyse PFAS in other estuarine samples.

Airborne particulate matter and diesel engine exhaust on infrastructure construction sites in the Copenhagen metropolitan area.

Diesel engine exhaust (DEE) is carcinogenic and potentially hazardous for those working in close proximity to diesel-powered machines. This study characterizes workplace exposure to DEE and its associated particulate matter (PM) during outdoor construction activities. We sampled at 4 construction sites in the Copenhagen metropolitan area. We used portable constant-flow pumps and quartz-fiber filters to quantify personal exposure to elemental carbon (EC), and used real-time instruments to collect activity-based information about particle number and size distribution, as well as black carbon (BC) concentration. Full-shift measurements of EC concentration ranged from < 0.3 to 6.4 µg/m3. Geometric mean (GM) EC exposure was highest for ground workers (3.4 µg/m3 EC; geometric standard deviation, GSD = 1.3), followed by drilling rig operators (2.6 µg/m3 EC; GSD = 1.4). Exposure for non-drilling-rig machine operators (1.2 µg/m3 EC; GSD = 2.9) did not differ significantly from background (0.9 µg/m3 EC; GSD = 1.7). The maximum 15-min moving average concentration of BC was 17 µg/m3, and the highest recorded peak concentration was 44 µg/m3. In numbers, the particle size distributions were dominated by ultrafine particles ascribed to DEE and occasional welding activities at the sites. The average total particle number concentrations (PNCs) measured in near-field and far-field positions across all worksites were 10,600 (GSD = 3.0) and 6,000 (GSD = 2.8)/cm3, respectively. Sites with active drilling rigs saw significantly higher average total PNCs at their near-field stations (13,600, 32,000, and 9,700/cm3; GSD = 2.4, 3.4, and 2.4) than sites without (4,700/cm3; GSD = 1.6). Overall, the DEE exposures at these outdoor construction sites were below current occupational exposure limits for EC (10 µg/m3 in Denmark; 50 µg/m3 in the European Union), but extended durations of exposure to the observed DEE levels may still be a health risk.

Source Profile Analysis, Source Apportionment, and Potential Health Risk of Ambient Particle-Bound Polycyclic Aromatic Hydrocarbons in Areas of Specific Interest

Ambient particulate matter (PM10) and its chemical composition in polycyclic aromatic hydrocarbons (PAHs) were studied in areas of specific interest, between September 2015 and July 2016. The principal aim of this study was to assess the different PAH source profiles in each area, as well as their potential health risk. In particular, the studied areas were (a) the semiurban industrialized zone of the Municipality of Peloponnese (Meligalas, Messini) of Messinia prefecture, due to the intensive olive-productive activity in the extensive area, (b) the industrialized zone of Oinofyta in Voiotia prefecture, and (c) the urban/traffic center of Athens (Aristotelous). Intense spatial and seasonal variations in PAH levels were observed among the study areas collectively, but also for each one individually. During the winter period, the total PAHs average concentration was 11.45 and 9.84 ng/m3 at Meligalas–Skala (S1, S2 stations), 8.84 ng/m3 at Messini (S3 station), and 6.30 ng/m3 at the center of Athens (Aristotelous). During the summer campaign, the corresponding levels were 0.99, 1.20, and 0.70 ng/m3 (S1, S2, and S3 stations), and 5.84 ng/m3 (Aristotelous), respectively. The highest potential cancer risk of the PAHs mixture was estimated based on winter season measurements taken at the Municipality of Peloponnese. In order to determine PAH sources, two different source apportionment techniques were applied, i.e., diagnostic ratios (DRs) and the positive matrix factorization (PMF) model.

Evolution of Physical and Chemical Characteristics of Atmospheric Precipitation and Its Significant Impacts on the Environment in Beijing

Atmospheric precipitation samples were collected in 2018, 2019, and 2021 in Beijing to study the concentrations and changes of the main metal elements and water-soluble ions； the wet deposition fluxes of heavy metals, water-soluble ions, dissolved inorganic nitrogen, and sulfur in the atmospheric precipitation and their impacts on the ecological environment； and the scavenging mechanisms of the typical precipitation to atmospheric pollutants during the study period. The results showed that the precipitation in Beijing during the study period was mostly neutral or alkaline, and the frequency of acid rain occurrence was very low, only accounting for 3.06%. The total concentrations of major metal elements in 2018, 2019, and 2021 were （4 787.46 ±4 704.31）, （7 663.07 ±8 395.05）, and （2 629.13 ±2 369.51） μg·L-1, respectively. The total equivalent concentrations of ions in 2018, 2019, and 2021 were （851.68 ±649.16）, （973.98 ±850.94）, and （644.31 ±531.16） μeq·L-1, respectively. The interannual changes in major metal elements and ions followed the order of 2019 &gt; 2018 &gt; 2021. The seasonal average total concentrations of major metal elements in spring, summer, autumn, and winter were （9 624.25 ±7 327.92）, （4 088.67 ±5 710.14）, （3 357.68 ±3 995.64）, and （6 203.19 ±3 857.43） μg·L-1, respectively, and the seasonal average total equivalent concentrations of ions in spring, summer, autumn, and winter were （1 014.71 ±512.21）, （729.83 ±589.90）, （724.35 ±681.40）, and （1 014.03 ±359.67） μeq·L-1, respectively, all presenting the order of spring &gt; winter &gt; summer &gt; autumn. NO3- and SO42- were the main acid-causing ions in precipitation, whereas NH4+ and Ca2+ were the main acid-neutralizing ions. The wet deposition fluxes of the heavy metal Cd were very low [（0.05 ±0.01） mg·（m2·a）-1], only accounting for （0.13 ±0.04）% of the total wet deposition fluxes of main metal elements； however, its soil safety years were 291 years, significantly lower than those of other heavy metals, displaying that its ecological risk was relatively the highest. The total wet precipitation flux of water-soluble ions NH4+, Ca2+, NO3-, and SO42- accounted for （85.72 ±2.18）% of the wet precipitation flux of total ions, suggesting that their comprehensive impact on the ecological environment might have been higher. DIN wet deposition flux was mainly characterized by NH4+-N, which had a positive impact on the ecological environment in summer. SO42--S wet deposition flux was higher in summer, so its positive impact on the ecological environment was also greater. The scavenging effects of atmospheric precipitations to pollutants from the air were impacted by various factors, and the synergism effects of these factors could directly influence the scavenging mechanisms of precipitation to pollutants.