Characteristics of surface ozone pollution and its correlations with meteorological factors: the case of Xiangtan.

Based on ozone (O3) monitoring data for Xiangtan and meteorological observation data for 2020-2022, we examined ozone pollution characteristics and the effects of meteorological factors on daily maximum 8-h average ozone (O3-8h) concentrations in Xiangtan. Thus, we observed significant increases as well as notable seasonal variations in O3-8h concentrations in Xiangtan during the period considered. The ozone and temperature change response slope (KO3-T) indicated that local emissions had no significant effect on O3-8h generation. Further, average O3-8h concentration and maximum temperature (Tmax) values showed a polynomial distribution. Specifically, at Tmax < 27 °C, it increased almost linearly with increasing temperature, and at Tmax between 27 and 37 °C, it showed an upward curvilinear trend as temperature increased, but at a much lower rate. Then, at Tmax > 37 °C, it decreased with increasing temperature. With respect to relative humidity (RH), the average O3-8h concentration primarily exceeded the standard value when RH varied in the range of 45-65%, which is the key humidity range for O3 pollution, and the inflection point for the correlation curve between O3-8h concentration and RH appeared at ~55%. Furthermore, at wind speeds (WSs) below 1.5 m∙s-1, O3-8h concentration increased rapidly, and at WSs in the 1.5-2 m∙s-1 range, it increased at a much faster rate. However, at WSs > 2 m∙s-1, it decreased slowly with increasing WS. O3-8h concentration also showed the tendency to exceed the standard value when the dominant wind directions in Xiangtan were easterly or southeasterly.

Contribution and Effects of PM2.5-Bound Lead to the Cardiovascular Risk of Workers in a Non-Ferrous Metal Smelting Area Considering Chemical Speciation and Bioavailability.

Lead is known to have toxic effects on the cardiovascular system. Owing to its high concentration, transmission range, and absorption efficiency in organisms, inhalation of fine particulate matter (PM2.5)-bound lead (PM2.5-Pb) may cause significant cardiovascular damage. However, the contribution and adverse effects of PM2.5-Pb on workers and residents in non-ferrous metal smelting areas are not fully understood. In this work, the concentration and chemical speciation of PM2.5-Pb were analyzed to determine its pollution characteristics at a typical non-ferrous metal smelting site. A panel study conducted among factory workers revealed that PM2.5-Pb exposure makes an important contribution to the human absorption of Pb. Although the chemical speciation of PM2.5-Pb suggested poor water solubility, a high bioavailability was observed in mice (tissue average value: 50.1%, range: 31.1-71.1%) subjected to inhalation exposure for 8 weeks. Based on the bioavailability data, the relationship between PM2.5-Pb exposure and cardiovascular damage was evaluated in animal simulation experiments. Finally, a damage threshold and cardiovascular-specific risk assessment model were established for the non-ferrous metal smelting area. Our project not only accurately estimates the risk of PM2.5-bound heavy metals on the cardiovascular system but also offers a scientific basis for future prevention and therapy of PM2.5-Pb-related diseases.

Pollution characteristics and microbial community succession of a rural informal landfill in an arid climate.

Informal landfills pose potential threats to the environment and human health due to the lack of anti-seepage measures. However, little research has been conducted on the distribution of pollutants in informal landfill sites situated in arid climates, as well as the underlying interaction mechanisms between environmental factors and microbial structure. In this study, we sought to investigate the pollution characteristics and microbial community succession of the landfill in northern China. The results revealed that heavy metals in the landfill showed poor mobility and migration. The lower layers of the garbage samples had higher water-soluble contents of heavy metals compared to the upper layers. The landfill-derived dissolved organic matter (DOM) was found to originate from microbial production, and four fluorescent components were identified, including fulvic acid-like substances, humus-like substances, and protein-like components. Fluorescence intensity and humification degree increased with increasing depth. The microbial diversity and richness decreased with sampling depth. The most abundant phyla in the samples were Proteobacteria, unidentified_Bacteria, Bacteroidota, Firmicutes, Myxococcota, Gemmatimonadota, Actinobacteria, and Deinococcota. As the sampling depth increased, Proteobacteria decreased, while Bacteroidota and Firmicutes showed a remarkable increase, with little variation observed in the other phyla. The partial least-squares path model (PLS-PM) results indicated that pH had the most significant effect on microbial abundance and diversity (direct effect value = -5.560), while DOM and heavy metals had the opposite effect, with direct effects of 1.838 and 3.231, respectively. DOM was identified as the driving factor for the variation in other environmental factors. The redundancy analysis (RDA) showed that the dominant genera were greatly influenced by Cu, humic-like substances, and protein-like substances. Among them, Bacillus, Alcanivorax, Devosia, and Chryseolinea may play important roles in the remediation of landfills. Our study not only gains a deeper understanding of the pollution risk of informal landfills in arid climates, but also provides a scientific basis for the future treatment and restoration of contaminated sites associated with landfills.

Human biomonitoring of heavy metals exposure in different age- and gender-groups based on fish consumption patterns in typical coastal cities of China.

The study aimed to investigate heavy metals (HMs) concentrations in human hair based on fish consumption patterns in Qingdao, Xiamen, and Zhoushan. The (HMs) concentrations were determined using acid digestion and an inductively coupled plasma mass spectrometer (ICP-MS, NexION 300X, PerkinElmer). The associated health risks were investigated using risk assessment models described by the United States Environmental Protection Agency (USEPA). The order of fish HMs concentration in Qingdao was CdCrCu>Pb>Cr>As>Cd in all three study areas. The hair Zn concentration in 28 % of the studied population exceeded the safety standards. Overall, the hair HMs concentration was found to be high in middle-aged groups (19-45 and 45-59), and the hair HMs concentrations were high, especially in the case of females. A significant correlation was noticed between hair As (0.119; p < 0.05), Cr (0.231; p < 0.05),) and Cu (0.117; p < 0.05),) and fish consumption frequency. High Odd ratios (>2) were noticed for As, Cu and Zn in high fish-eating frequency. A significant non-carcinogenic risk was noticed in human Cr exposure (1.10E+00) in Xiamen, and the hazard index values indicated non-carcinogenic risk in Xiamen and Zhoushan. The carcinogenic risk for human As exposure (2.50E-05-7.09E-03) indicated a significant cancer risk.

Identification of priority pollutants at an integrated iron and steel facility based on environmental and health impacts in the Yangtze River Delta region, China.

Emissions from the iron and steel industry are a major source of air pollution. To investigate the composition characteristics, estimate the secondary transformation potential, and assess the ecological risk and human health risks of air pollutants from iron and steel industry, field measurements of volatile organic compounds (VOCs) and trace metals (TMs) were conducted simultaneously from 2020 to 2022 in the Yangtze River Delta (YRD) region, China. The average mixing concentration of VOCs (Σ64VOCs) was 58.2 ppbv. Alkanes, alkenes and aromatics were the major components. Benzene and ethylene were the most abundant VOC species. In the O3 season, the calculated OH loss rates (LOH) and ozone formation potential (OFP) were 10.87 S-1 and 181.74 ppbv, respectively, which increased 39.54% and 21.51% compared to the non-O3 season. Furthermore, the O3-VOCs-NOx sensitivity indicated that O3 formation was under the VOCs-limited regime. The average concentration of total 10 trace metals (Σ10TMs) was 226.8 ng m-3, Zn, Pb and Mn were the top abundant TM species. The results also found that Se was extremely contaminated; Pb and Zn was heavily to extremely contaminated; Cu, As and Ni were moderately to heavily contaminated. For lifetime cancer risk, the cumulative carcinogenic risks were 1.84E-5 for children, 6.14E-5 for adults and 1.83E-5 for workers. The carcinogenic risks of individual chemicals cannot be ignored, especially for Cr, Ni, benzene and 1,3-butadiene. The hazard index values for workers and residents were 0.53 and 2.23, respectively, suggesting a high non-carcinogenic risks to the exposed population. These findings deepen the understanding of the pollutant character of the iron and steel industry, and provide theoretical support for policy development on O3 pollution treatment and human health in the YRD region, China. For the study area, we recommend utilizing high-quality raw coal, reducing the volatile hydrocarbon content in the sinter feed, and installing absorption device for highly reactive VOC components at the exhaust outlet.

Source and migration patterns of heavy metals and human health risk assessment of heavy metals in soil-corn straw-flue gas system.

The process of rapid urbanization in Northeast China has resulted in severe heavy metal pollution in the environment. In this study, we investigated the characteristics of heavy metal pollution in soil-corn straw and its combustion flue gas system, and the health risks of heavy metal pollution. The results showed that Cu and Zn in soil were more easily absorbed by corn straw roots. Heavy metals in soil, corn straw and flue gas from corn straw burning all pose some health risk to humans, and are more harmful to children than adults. The concentrations of heavy metals in both soil and flue gas from corn straw burning have reached extremely high ecological risk. The main sources of heavy metal elements in soils are, in order, industrial production, agricultural production activities and metallurgical production. This study highlights the key issues of heavy metal contamination in soil-corn straw and its combustion flue gas system, provides an auxiliary guide for the next step in analyzing the transfer mechanisms, and suggests a rational approach to mitigate heavy metal contamination.

Contamination, ecological-health risks, and sources of potentially toxic elements in road-dust sediments and soils of the largest urban riverfront scenic park in China.

Identifying the contamination and sources of potentially toxic elements (PTEs) in road-dust sediment (RDS) and the surrounding greenspace soil of urban environments and understanding their ecological-health risks are important for pollution management and public health. The contamination characteristics, ecological and probabilistic health risks, and source apportionment of eight PTEs (Cd, Pb, Cr, Cu, Ni, As, Zn, and Hg) in the Yellow River Custom Tourist Line of Lanzhou, which is the largest open urban riverfront scenic park in China, were investigated. The results showed that all the RDS PTE mean concentrations exceeded their soil background values, whereas for the surrounding greenspace soils, the concentrations of the PTEs, except for Cr and Ni, were also higher than their local background levels. Moreover, the RDS-soil system was mainly contaminated by Cd, Zn, Pb, Cu, and Hg to varying degrees, and the integrated ecological risks of PTEs in the RDS and soil were high and considerable at most sites, respectively. The probabilistic health risk assessment results demonstrated that the non-carcinogenic hazard risk for humans was negligible, but the total carcinogenic risks should be considered. Source apportionment using a positive matrix factorization model combined with multivariate statistical analyses revealed that Cr, Ni, and As in the RDS-soil system were from natural and industrial sources, Cd, Pb, Zn, Cu came from vehicle emissions and pesticide and fertilizer applications, and Hg was from natural and industrial sources and utilization of pesticides with fertilizers. This work provides scientific evidence for urban planning and human health protection in urban environments.

Distribution, sources, and risk assessment of polycyclic aromatic hydrocarbons (PAHs) in Kaokaowusu river sediments near a coal industrial zone.

This study systematically analyzed the contents, compositions, and sources of polycyclic aromatic hydrocarbons (PAHs) in river sediments near an important energy and chemical base in northwest China. In addition, their possible adverse effects on the ecology and human health were assessed. The PAH concentrations in this study area ranged from 2641.28 to 16783.72 (ng/g dw). PAHs of medium molecular weight (3-ring and 4-ring) showed the largest proportion, followed by PAHs of higher molecular weight (5-ring and 6-ring). The results of molecular diagnostic ratios and principal component analysis revealed that PAHs in the region have complex sources, with incomplete combustion of local fossil fuels and traffic exhaust factors being the main sources. The total toxic equivalent concentration of PAHs varied from 10.05 to 760.26 ng/g, and according to the sediment quality guidelines, PAHs have high potential ecological risk in the lower reaches of the river. The mean effect range-median quotient for the region was 0.46, and the combined ecological risk was at moderate to high levels (21% probability of toxicity). The lifetime carcinogenic risks for adults and children exposed to PAHs were 2.95 × 10-3 and 1.87 × 10-2, respectively, which are much higher than the limit of 10-4, indicating moderate to high potential cancer risks. Therefore, the local government should consider taking some environmental remediation measures. This study can provide theoretical support for pollution prevention measures and ecological restoration strategies for rivers in resource-rich areas.

Distribution and pollution characteristics of organophosphate esters: reflected by tree rings of arbor species.

Organophosphate esters (OPEs) are emerging pollutants. Currently, research on OPEs in tree rings is still limited. In this study, tree rings of five arbor species from Sichuan Province, China, were sampled to study the occurrence and distribution of six OPEs, which were quantitatively analyzed by gas chromatography-mass spectrometry (GC-MS). The total concentrations of OPEs in all samples ranged from 189.79 (Fir species) to 341.23 ng/g (Toona sinensis), with average concentration of 284.77 ± 46.66 ng/g. So, arbor could be used as good passive samplers for OPEs. The levels of OPEs among five arbor species showed no significant difference (p = 0.668 > 0.05), suggesting that the pollution status of OPEs in a region or country could be roughly assessed by any arbor tree species. In this study area, tris(2-butoxyethyl) phosphate (TBEP) was the dominant OPEs followed by tri(2-chloroethyl) phosphate (TCEP). Tris(2-ethylhexyl) phosphate (TEHP) and tri-n-butyl phosphate (TnBP) showed relatively stable concentrations in each arbor species, while the other four OPEs including TBEP, triphenyl phosphate (TPhP), tri(chloropropyl) phosphate (TCPP) and TCEP had significantly different concentrations. Interestingly, the absorption and accumulation of OPEs by tree rings of arbor species were quite different from that of inorganic elements reported by other studies.

Pollution characteristics and source identification of farmland soils in Pb-Zn mining areas through an integrated approach.

Long-term mining activities have caused serious heavy metals contamination of farmland soils. In this study, we investigated the concentrations, distributions, accumulations, potential ecological risk, and sources of eight heavy metals in farmland soils of Pb-Zn mining areas. According to the soil standard GB15618-2018, Cd was the most contaminated, followed by Pb and Zn. The geo-accumulation index showed that Pb, Zn, Cd, and Hg accumulated seriously. The potential risk index indicated that Cd, Hg, and Pb were the main environmental risk elements. An integrated approach combining multivariate statistical analysis, PMF, and GIS mapping was used to analyze the sources of heavy metals. Four main sources were identified and quantified: (1) mining activities source, the main source of Cd (71.09%) and Zn (61.88%); (2) agricultural activities source, dominated by Hg (73.01%); (3) atmospheric deposition sources, with Pb (85.11%) as the main contributor; (4) natural source, characterized by Cr (72.96%), Ni (66.04%), As (55.98%) and Cu (37.70%). This study would help us understand the pollution characteristics and sources of farmland soils in mining areas and provide basic information for the next step of pollution control and remediation.

Residual status and source analysis of phthalate esters in Ulungur Lake, China.

Ulungur Lake is the largest lake in northern Xinjiang and undertakes important aquatic tasks. It is the No. 1 fishing ground in northern Xinjiang, and the problem of persistent organic pollution in the water has received much attention. However, there are few studies on phthalate esters (PAEs) in the water of Ulungur Lake. Understanding the pollution levels, distribution characteristics and sources of PAEs is of great significance for the protection and prevention of water. Fifteen sampling sites are established in Ulungur Lake to collect water samples during flood and dry periods, then seventeen PAEs are extracted from the water samples and purified by liquid-liquid extraction-solid-phase purification. Gas chromatography-mass spectrometry is used to detect the pollution levels and distribution characteristics of the 17 PAEs and analyse their sources. Results show that the concentrations of PAEs in the dry and flood periods are 0.451-9.97 µg/L and 0.0490-6.38 µg/L, respectively. The concentration of ∑PAEs with time is characterised by the dry period > the flood period. The change in flow is the main reason for the diverse concentration distributions of PAEs in different periods. The concentration of ΣPAEs in the dry period is much lower on the side near the lake entrance of the Ulungur River and Irtysh River. In the dry period, PAEs mainly come from chemical production and the use of cosmetics and personal care products; in the flood period, they mainly come from chemical production. River input and atmospheric sedimentation are the main sources of PAEs in the lake.

Pollution characteristics and health risk assessment of polycyclic aromatic hydrocarbons and nitrated polycyclic aromatic hydrocarbons during heating season in Beijing.

Polycyclic aromatic hydrocarbons (PAHs) and their nitrated derivatives (NPAHs) attract continuous attention due to their outstanding carcinogenicity and mutagenicity. In order to investigate the diurnal variations, sources, formation mechanism, and health risk assessment of them in heating season, particulate matter (PM) were collected in Beijing urban area from December 26, 2017 to January 17, 2018. PAHs and NPAHs in PM were quantitatively analyzed via gas chromatography-mass spectrometry (GC-MS) . Average daily concentrations of PAHs and NPAHs were (78 ± 54) ng/m3 and (783 ± 684) pg/m3, respectively. The concentrations of them were significantly higher at nighttime than at daytime, and NPAHs concentrations were 1-2 orders of magnitude lower than PAHs concentrations. In the heating season, the dominant species of PAHs include benzo[b]fluoranthene, fluoranthene, pyrene, and chrysene, while 9-nitroanthracene, 2+3-nitrofluoranthene, and 2-nitropyrene were dominant species for NPAHs. NPAHs were found to have a single peak during heating and to be primarily distributed in the 0.4-0.7 µm particle size. Primary emissions such as biomass burning, coal combustion, and traffic emissions were the major sources of PAHs. NPAHs were produced by the primary source of vehicle emissions and the secondary reaction triggered by OH radicals, as well as biomass burning during daytime. According to the health risk assessment, the total carcinogenic risk was higher in adults than in children. While upon oral ingestion, the carcinogenic risk in children was higher than that of adults, but the risk of adults was higher than children through skin contact and respiratory inhalation.

Heavy metals pollution characteristics and risk assessment in sediments and waters: The case of Tianjin, China.

Potential health and ecological risks due to heavy metal pollution in surface waters and sediments were evaluated based on a health risk assessment model and a potential ecological risk index method. Combined with the reclamation progress of Tianjin Nangang Industrial Zone, in China, a survey was carried out in the area dealing with heavy metals concentrations in surface waters and sediments, covering from 2008 to 2018. Specifically, concentrations were determined for As, Cd, Hg, Cu, Pb, and Zn. The results show that As、Cd、Hg、Cu 、Pb、Zn average concentrations in surface water were 0.99 µg/L∼1.27 µg/L, 0.13 µg/L∼0.63 µg/L, 0.03 µg/L∼0.13 µg/L, 1.5 µg/L∼4.65 µg/L, 1.25 µg/L∼4.7 µg/L, 13.5 µg/L∼20.99 µg/L and which average concentrations in sediment were 5.12 mg/kg∼12.34 mg/kg, 0.12 mg/kg∼0.18 mg/kg, 0.04 mg/kg ∼0.087 mg/kg, 13.45 mg/kg∼31.92 mg/kg, 13.2 mg/kg ∼21.26 mg/kg, 21.58 mg/kg ∼77.21 mg/kg, respectively. The background values of the Hailuan River basin near the study area were taken as the reference and compared with the national sediment quality standards a tell us the quality of the sediments in Tianjin Nangang coastal area being good. As regards the characteristics of pollution, heavy metals showed a high concentration in 2008 and then decreased significantly, which related to the dredging of large amounts of contaminated surface sediment during port construction. According to the phase equilibrium partition coefficient (Kp) and temporal and spatial distribution characteristics of heavy metals, sediments can be seen as an obvious sink for lead, with this element being mainly affected by exogenous input in coastal seawater. Zn, As, Cd, and Hg contents in surface water were greatly affected by the endogenous release from sediments. The results of the environmental risk assessment showed that the main environmental health risk of Tianjin coastal waters was carcinogenic, and specifically due to As. The potential heavy metals ecological risk assessment results of surface sediments were mild for the affected areas.

Pollution characteristics and source analysis of heavy metals in surface sediments of Luoyuan Bay, Fujian.

The concentrations of eight heavy metals, V, Cr, Co, Ni, Cu, Zn, Cd, and Pb, were analyzed to explore the environmental pollution characteristics, ecological risk levels, and sources of heavy metals in the surface sediments of Luoyuan Bay in Fujian Province. The results indicated that the mean concentrations of V, Cr, Co, Ni, Cu, Zn, Cd, and Pb were 110.44, 97.76, 17.35, 41.99, 36.78, 137.26, 0.09, and 35.81 mg⋅kg-1, respectively. The mean concentrations of Cr, Cu, and Zn exceeded the first category of the marine sediment quality standards, indicating a moderate regional comprehensive potential ecological hazard level. Due to variable hydrodynamic conditions, high concentrations of heavy metals were observed in the north and low concentrations were observed in the south, with high values generally recorded near steel plants and shipyard docks. Correlation and principal component analyses revealed that the V, Al, Co, Ni, and Pb originated from the weathering and erosion of rocks, and industrial wastewater discharge. Contrastingly, Cu, Zn, Cr, and Cd were mainly associated with the transportation and repair of ships, and marine aquaculture activities.

Soil contamination with cadmium and potential risk around various mines in China during 2000-2020.

Cadmium (Cd) pollution in mining areas is the most important challenge for soil environment management in China. Assessing the actual Cd pollution risk in various mining areas and identifying the core areas requiring supervision can provide a basis for government departments and industries to carry out detailed further investigations in key areas. In this study, we collated published data on metal mine circumjacent soil contaminated by Cd in China from 2002 to 2020 to conduct a comprehensive study on soil cadmium pollution and ecological and health risks in mining areas. The temporal and spatial variations of Cd concentrations and the pollution source were investigated. Results indicated that the Cd concentration in soil was strongly associated with the types of mining area. The Cd pollution in the circumjacent soil of lead-zinc and tungsten mines with high heavy metal pollution discharging coefficient was more serious than the soil around other mines. Identification of temporal and spatial variations for soil Cd in China indicated that the high Cd concentrations were found in the central, southern, and southwestern regions of China, and the distribution of mining activities in these regions are relatively concentrated. Meanwhile, a temporal turning point in the mean soil Cd concentration occurred in these regions in 2012, which indicated that the heavy metal control management policy implemented by the government was effective. The ecological risk of soil Cd pollution around mining areas was moderate to high. Health risk assessment showed that some regions adjacent mining areas had a high non-carcinogenic risk, notably, lead-zinc and tungsten mining areas were more serious. Supervision should focus on reducing ecological risks and protecting the safety of agricultural products rather than concentrating on health risks. The research results provide a reference for the priority management of contaminated soil in mining areas.

Pollution, Exposure and Risk of Biogenic Amines in Canned Sea Fish: Classification of Analytical Methods Based on Carbon Spheres QuEChERS Extraction Combined with HPLC.

This study investigated the pollution characteristics, exposure levels and health risk assessments of seven kinds of biogenic amines (BAs) in eight varieties of canned sea fish products (n = 131) on the Chinese market. Carbon spheres QuEChERS mixed dispersion solid phase extraction combined with HPLC was used for the classification and analysis of batch samples. The average recovery of single BAs obtained by this method is 92.3~97.7%, and the relative standard deviation is 1.9~4.8%. Different varieties of samples have different degrees of pollution, the mass concentration of single BAs range 0.45~27.74 mg/kg, and the total concentration of ΣBAs range 18.77~368.50 mg/kg, of which the concentration of Σ4BAs range 11.53~368.50 mg/kg. The composition of four BAs is mainly putrescine, cadaverine, histamine and tyramine, which always play an important role in the exposure level and risk assessment of samples. The exposure level of BAs in the human body ranges 67.03~209.52 µg∙kg−1∙d−1. The health risk assessment shows that the gender trend of exposure risk level of BAs is male > female (young age), female > male (middle and old age), the age trend is young age > old age > middle age, and the regional trend is city > countryside. The food safety index of BAs in samples is 0.0062~0.0195, which is far less than 1, so the risk is within the controllable range.

Characterization, risk assessment and resource potential of sediments in the black-odor water in Hunan, China.

The black-odor water in urban water bodies is increasingly found, resulting in serious atrophy of water bodies and degradation of water ecosystems. At present, the pollution status of the sediments as an internal source still remains much unknown. In order to assess the pollution status of black-odor water sediments, the content of total nitrogen, total phosphorus, organic matter and heavy metals in the sediments were determined by taking the black-odor water sediments in urban areas of Hunan Province as the research object. Geoaccumulation and potential ecological risks index methods were used to evaluate heavy metal pollution in the sediments, and comprehensive pollution index method was used to evaluate nitrogen and phosphorus nutrient pollution in the sediments so as to provide pertinent information for urban black-odor water treatment. Finally, resource recovery potentials of sediments in black-odor water were revealed. The results could be beneficial for evaluation of sediments in black-odor water bodies.

Pollution characteristics of soil heavy metals around two typical copper mining and beneficiation enterprises in Northwest China.

In order to investigate the situation of heavy metal pollution in the heavy metal industry in Gansu Province, a large copper mining province, two large and typical copper mining and beneficiation enterprises with differences in topographic features, climatic conditions, and soil types were selected as the target of this study based on similar ore types and beneficiation processes. Around these two enterprises, geochemical baselines of the six heavy metals were established, while the degree of local soil heavy metal pollution and potential hazards to humans were assessed based on statistical analysis, single-factor and multi-factor index analysis, and health risk evaluation models. In addition, Spearman's correlation analysis and hierarchical cluster analysis were used to explore the intrinsic association between each heavy metal in the two mining industries to reveal the pattern of soil heavy metal pollution in the copper mining and beneficiation industry and to propose targeted measures to improve and prevent soil heavy metal pollution. The results showed that the heavy metal pollution in the soil around Shengxi Mining Co., Ltd. of Subei County (SX enterprise) was higher than that around Yangba Copper Co., Ltd. of Gansu Province (YB enterprise), but the two enterprises had similar patterns of pollution, with an overall medium level of pollution. The carcinogenic and non-carcinogenic risks for children and adults were within acceptable limits for both enterprises. Besides, the correlation between the different heavy metals to similarity in their sources of contamination and the different degrees of association between the soil heavy metals of the two enterprises due to their environmental characteristics.

Atmospheric carbonyls in a heavy ozone pollution episode at a metropolis in Southwest China: Characteristics, health risk assessment, sources analysis.

Ambient carbonyls were continuously observed in the field during a heavy ozone pollution episode in Chengdu, China from August 4 to August 19, 2019, and the pollution characteristics, atmospheric photochemical reactivity, human health risk, and sources of carbonyls were analyzed. Fifteen carbonyls were quantified with average total mixing ratios of 20.38 ppbv Formaldehyde (9.86 ppbv), acetone (4.41 ppbv), and acetaldehyde (3.57 ppbv) were the three most abundant carbonyls. During the heavy ozone pollution episode, the concentration of carbonyls was found to be higher on pollution days than on the clean days, and relatively higher in the daytime, especially at noon on the pollution days. This was influenced by the intensity of photochemical reactions and precipitation. The "weekend effect" with the concentration of carbonyls was higher on the weekends than on the weekdays was pointed out. Formaldehyde, acetaldehyde and hexaldehyde were the dominant oxidative species during the observation. The carcinogenic and non-carcinogenic risk values of formaldehyde and acetaldehyde were higher on pollution days than on clean days, and these values were higher compared with those of other cities in China and abroad. Long-term exposure to these compounds should therefore be avoided. Diagnostic ratios and correlation analysis together with backward trajectory analysis showed that primary emission and secondary formation accounted 66%-76% and 24%-34% of carbonyls in Chengdu, respectively, with primary emission being the main sources of carbonyls, and carbonyls from the surrounding cities and emission from natural sources also had a significant contribution to the carbonyls in Chengdu.

Pollution characteristics, sources and health risk of metals in urban dust from different functional areas in Nanjing, China.

Urban dust is an important medium of potential toxic metal (PTM) pollution that affects human health and the urban ecosystems. A total of 374 fugitive dust samples were collected in Nanjing, a fast-developing city in southern China, including six sub-types of dust (residential district, commercial district, industrial district, traffic district, cultural and educational district, green land). Chemical analysis of eighteen metal elements by inductively coupled plasma mass spectrometry was carried out to establish the sub-type sources profiles of fine particles for fugitive dust. The results show that these metals (Cu, Zn, Se, Sr, Mo, Cd, Sb, and Pb) are mainly from anthropogenic sources and present a high degree of pollution; Mn, As, and Ba are moderately affected by human activities and present a significant degree of pollution; Ni, Co, Cr, Tl, V, Be, and Ti mainly originate from natural sources and present significant, moderate and minimal degrees of pollution. For the dust types from different functional areas, the differences of enrichment factor (EF) values were relatively small. Metals were highly concentrated in dust from residential, cultural and educational district, which had high density population and would pose higher health risk. In all types of dust, the metals rich in crust (Ti, Mn, Ba, Sr) and the metals (Cu, Zn, Pb) closely connected with city activities were the main components. Factor analysis revealed that there were six main sources of metals in dust collected from Nanjing: industrial activity, building decoration, soil dust, metal smelting, traffic emissions, and brake abrasion. Generally, noncarcinogenic and carcinogenic health risks of metals found in dust are rarely found for children and adults based on health risk assessments. However, the noncarcinogenic risk of Pb in commercial districts for children should be noted because its hazard quotient was higher than the safety threshold level. For the accumulative health risk of eighteen metals, the noncarcinogenic risk values of dust from six functional areas for children were all over the threshold (1.0), whereas below 1.0 for adults. The difference between children and adults was relatively obvious. All accumulative risk values of carcinogenic metals did not exceed the carcinogenic risk threshold of 1 × 10-4, which suggested that no risk prevention measures were needed.