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The corresponding relationships between temperature, precipitation, and polycyclic aromatic hydrocarbon (PAH) concentration in a typical ombrotrophic peatland in Dajiuhu, Shennongjia, were quantitatively characterized by field sampling tests validated with simulation experiments. The PAH concentrations of peat cores in Dajiuhu peatland ranged from 262 to 977 ng·g

Variations of levels, possible source and air mass transmission were investigated for 16 USEPA priority-controlled PAHs in PM2.5 during 2018 Chinese Spring Festival (CSF) in Xiangyang City, central China which is the North-South pollutant airmass transport channel of China. Totally 37 samples were collected. Mass concentrations of Σ16PAHs for the Pre–CSF day (Pre–CSFD), during the CSF day (CSFD) and after the CSF day (Af–CSFD) are 33.78 ± 17.68 ng/m3, 22.98 ± 6.49 ng/m3, and 8.99 ± 4.44 ng/m3, respectively. High resolution samples showed that Σ16PAHs are higher in the morning (06:00–11:00) or afternoon (11:30–16:30), than those in the evening (17:00–22:00) and at night (22:30–05:30), whereas the result is reversed during the CSFD. Fireworks burning can obviously increase the mass concentration of PAHs. Air mass trajectory indicated that Xiangyang is a sink area of pollutants for northwest and southeast, and the sources of the northeast and southwest. The air mass only can be transmitted out through northeast and southwest. It is effective for improvement of air quality in Wuhan and Hunan to control fireworks emission in Henan and local areas. Fireworks burning was an important source for PAHs during CSFD, biomass, coal combustion, and traffic emission were the main sources of PAHs for Pre–CSFD and Af–CSFD periods. The health risk on the CSFD was higher than the acceptable levels, especially during the intensive fireworks burning, the risk value far exceed 1.0 × 10−4, controlling burning fireworks is required.

In order to investigate the heavy metal pollution level and distribution characteristics in different particle sizes, and to evaluate the health risk, 42 street dust samples were collected in January 2015 from Huangshi, as an industrial city in Central China. The results analyzed by flame atomic absorption spectrometry (FAAS) showed that the average content of Cu, Pb, Zn, Cd, Mn, and Fe in the fine particle diameter (< 25 μm) was 1041.12, 361.64, 890.00, 14.43, 3178.52, and 61841.79 mg kg−1, respectively. Meanwhile, the average content of Cu, Pb, Zn, Cd, Mn, and Fe in the coarse particle diameter (25 < D < 75 μm) was 1628.54, 401.52, 593.16, 9.54, 5316.07, and 76765.37 mg kg−1, respectively. Compared with other cities, the heavy metal pollution of street dust in Huangshi was more serious. The results indicated that heavy metals were more easily enriched in fine grains street dust, except for Cu, Mn, and Fe. The heavy metal elements showed obvious spatial heterogeneity in different regions, and the interference from human sources was greater. Heavy metals in Huangshi street dust are generally at moderate or higher pollution levels (except Fe), of which Cu and Cd are the most seriously polluted. Multivariate statistical analysis shows that the heavy metals in fine-grained street dust mainly come from traffic/industrial mixed sources (74.5%) and industrial sources (25.5%); the heavy-grained street dust heavy metals mainly come from mixed traffic/industrial sources (55.1%) and soil source (44.9%). For non-carcinogenic heavy metals, mainly through the hand-mouth contact pathway into the human body, there are also no non-carcinogenic health risks in both hand-mouth ingestion and dermal contact. For carcinogenic heavy metals, Cd in street dust did not have carcinogenic risk.

Huangshi City in Hubei Province, Central China is one of the most important mineral cities in the middle reaches of the Yangtze River, where haze occurred frequently in recent years due to coal-based metalsmelting. A haze was observed from January 13 to January 25, 2018 in Huangshi. To understand the levels, compositions, influencing parameters, and sources of PAHs during a process of haze generation and elimination, fine particulate matter (PM2.5) -bound polycyclic aromatic hydrocarbons (PAHs) were high-time-resolution measured (four samples per day) by gas chromatograph-mass spectrometry (GC-MS). The episode divided into three periods including before haze episode (BHE, 10 samples), during haze episode (DHE, 33 samples) and after haze episode (AHE, 4 samples) based on PM2.5 concentration. The average concentrations of Σ15PAHs at three different periods decreased as follows: DHE (30.52 ng m−3) > BHE (29.99 ng m−3) > AHE (14.24 ng m−3). 4- and 5-ring PAHs were the dominant species, and the proportion of 5- and 6-ring PAHs significantly increased DHE probably due to the local emissions (e.g., vehicle emissions) and the poor atmospheric dispersion conditions. PM2.5-bound PAHs were affected by gaseous pollutants (NO2, SO2, O3, and CO) and meteorological parameters (pressure, temperature, wind speed, wind direction, and relative humidity). Results of source apportionment indicated that PM2.5-bound PAHs were similar for three stages of this haze, mainly including vehicle exhaust emission, coal/biomass combustion, industrial process, and coke oven.

Polycyclic aromatic hydrocarbons (PAHs) and heavy metals (HMs) are persistent environmental issues. Secondary emissions are produced as a result of climate change and human activity. To observe spatio-temporal variations of PAHs and HMs and to discuss the sources as well as the source or sink of PAHs for sediment and peat, twelve surface sediment and surface water sites were chosen along the direction of the flow to down hole in the Dajiuhu area, simultaneously, surface peat and water samples were collected in peatland. Samples were continuously taken for three years (Sep. 2018, Sep. 2019, and Sep. 2020, respectively). The results showed that PAHs and HMs are common in sediment and peat. PAHs concentration is generally higher in peat and water, while HMs concentration is relatively higher in water and relatively low in sediment and peat, and the ecological risk of sediment was low. HMs in sediment are mainly affected by rock weathering, while PAHs are mainly affected by atmospheric deposition, biomass and coal combustion and vehicle emission. HMs and PAHs can be used as an indicator of rock weathering and human activity in Dajiuhu area, respectively. A water-sediment fugacity analysis revealed that peat is a sink for PAHs, confirming that it has a high capacity for adsorbing organic contaminants, and that sediments are secondary sources of PAHs that can release them into water. Attention should be paid to the increased fugacity fraction (ff) value in peatland, indicating that peat might be converted from a sink to a source of PAHs.

Twenty-one street dust samples were collected in Huanggang City, Hubei Province, Central China. Sixteen priority polycyclic aromatic hydrocarbons (PAHs) were determined by gas chromatography–mass spectrometry (GC-MS). Concentrations of ∑16PAHs ranged from 622.97 µg kg–1 to 4340.67 µg kg–1 with an average of 1862.10 µg kg–1. Among these PAHs, high-molecular-weight PAHs (four to six rings), which are the predominant PAH contributors in street dust, accounted for 55%–73% of the total PAHs. Mean concentrations of the PAHs among the four functional districts followed the order: education district > traffic area > business district > residential area. However, the individual PAH concentrations exhibited weak correlations with the total organic carbon. Based on the isomer ratios of the PAHs, biomass and coal combustion, and petroleum input were two key factors controlling PAH levels in this study. At a 95% confidence interval, the total incremental lifetime cancer risks for children, adolescents and adults approximated 10–6–1.5 × 10–5. These values were higher than the baseline value for acceptable risk (10–6), indicating a potential carcinogenic risk.

Twenty-one soil samples and two dominant plant species (Elsholtzia splendens and Imperata cylindrical) were collected in Tonglushan Cu–Fe deposit, central China. Chemical analysis results showed that the soil contained low-level nutrients and high concentrations of potentially toxic metals. The geoaccumulation index results indicated that the study area was polluted by Cu–Zn–Cd–Pb. The levels of Cu in plant species were highest, followed by Zn, Pb, and Cd. The highest levels of Zn (261 mg kg−1), Cd (6.33 mg kg−1) and Pb (12.6 mg kg−1) were found in the leaf of Elsholtzia splendens and the highest concentration of Cu (1158 mg kg−1) was found in the root of Imperata cylindrica. Potentially toxic metals uptake and accumulation abilities were investigated by the bioconcentration factor and translocation factor, respectively. The results suggested that the Elsholtzia splendens may be a suitable candidate for Cd clean up using phytoextraction.

Polycyclic aromatic hydrocarbons (PAHs) are a kind of organic pollutants with carcinogenic, teratogenic, and mutagenic effects. This study aims to assess the effects of changes in China's socio-economic indicators represented by energy consumption and number of motor vehicles, on PAHs and black carbon (BC) deposition. For this, a 50-cm peat core from Dajiuhu peatland, Central China, was collected and divided into 50 subsamples to establish a sedimentary record of about 200 years with radioactive 210Pb. The Σ16PAH concentration ranged from 212.67 to 830.10 ng·g-1, mainly composed of 2- and 3-ring PAHs, and BC ranged from 7.89 to 36.48%. The deposition characteristics of BC first increased and then decreased from the core bottom to the top. The predominant of the carcinogenic PAHs (C-PAHs) was Dibenzo[a,h]anthracene (DBA) before 1949, and then changed to Benzo[b]fluoranthene (BbF). Ratio of Fla/Pyr, (3+4)-ring/(5+6)-ring PAHs, and BaA/(BaA+Chr), IcdP/(IcdP+BghiP) suggested that long-range atmospheric transmission (LRAT) and pyrogenic were the main PAHs sources, but that local PAH emission contribution gradually increased since 1990, and mixed (petroleum and combustion) sources were the dominant since 2000. The high concentration of Phenanthrene (Phe) and Naphthalene (Nap) were likely from plant product. Furthermore, increased concentrations of 4-, 5-, and 6-ring PAHs showed significant correlations with increased coal and petroleum consumption and the number of motor vehicles, respectively, and this influence has strengthened after 2000. These were caused by rapid urbanization and industrialization following the implementation of the reform and opening up policy in 1978, and a new round of urbanization after 2000.

The sedimentary history of polycyclic aromatic hydrocarbons (PAHs) and organochlorine pesticides (OCPs) over the past 140 years in a lake sediment core from Huixian karst wetland was reconstructed. The total PAHs and OCPs concentrations ranged from 40.0 to 210 ng g−1 and 0.98 to 31.4 ng g−1, respectively. The vertical distribution of PAHs and OCPs in different stages was great consistent with the history of regional socio-economic development and the usage of OCPs. As the indicators of socio-economic development, gross domestic product (GDP), population, energy consumption, highway mileage, and private vehicles correlated with the PAHs concentrations, indicating the impact of human activities on PAHs levels. The PAHs and OCPs concentrations were also affected by environmental changes in the wetland, as reconstructed by total organic carbon (TOC), sand, silt, clay, quartz, and calcite in sediments. Redundancy analysis (RDA) results showed TOC was the dominant factor to explain the concentrations of PAHs and OCPs with the explanation of 86.7% and 43.5%, respectively. In addition, TOC content had significantly positive correlation with PAHs (0.96, p

To elucidate the concentrations, spatial distribution, sources, and risk of sixteen polycyclic aromatic hydrocarbons (PAHs) and twenty-four organochlorine pesticides (OCPs), thirteen sites were chosen for collecting water, sediment, and soil samples from Daye lake in April 2019. All pollutants were frequently observed in three media of Daye lake. Higher concentrations of OCPs were determined in the soil whereas PAHs were dominant among sediment samples. However, the water of Daye lake is contaminated with both of the pollutants. In water, ΣDRINs, ΣDDTs, ΣHCHs and LMW PAHs accounted for 22.1%, 19.6%, 17.9% and 85.5%, respectively. Among sediments, OCPs and PAHs were ranged from 1.53–51.38 ng·g−1 and 14.38–4659.66 ng·g−1, respectively. While soil accounted for a larger percentage of heptachlorepoxide i.e. 96.5% and HMW PAHs i.e. 82.7%. Furthermore, the low α-to γ-HCH ratio suggested fresh input of HCH and the higher ratio of (DDE + DDD)/DDT determined the historical use of DDT. Additionally, diagnostic molecular ratio along with principal component analysis evaluated that PAHs mainly came from fossil fuel, biomass, and coal combustion. Moreover, ecological risk assessment of Daye lake indicated that the carcinogenic PAHs in water and soil can pose 10% risk to the environment also OCPs in sediments has a visible effect on ecology. According to incremental lifetime cancer risks (ILCRs) evaluation, OCPs have negligible to low cancer risk among all sites for water, soil, and sediments while PAHs value fluctuate in the midst of 10−6 to 10−2 which shows the potential risk of cancer on children as well as adults. Therefore, measures should be taken to control them in time.

Huanggang City in central China, is a regional site connect with the north air mass from Xiangyang and Suizhou in Hubei Province and the eastern air mass from Dabie-shan which located at the junction of Hubei and Anhui Province. To enrich the aerosol database in central China and provide reference for the control of air pollution in Huanggang City and surrounding cities in central China, totally 62 PM2.5 samples were collected during the year 2018 for season variation (January 2018–January 2019, once a week) and 16 priority PAHs were analyzed. The annual average concentrations of PM2.5 and PM2.5-bound PAHs were 60.4 ± 38.6 μg m−3 and 7.35 ± 6.79 ng m−3, respectively. Positive matrix factorization (PMF) model showed that the main sources of PM2.5-bound PAHs were vehicle emissions (56.8%), coal and biomass burning (29.5%) and petroleum sources (13.7%). PM2.5 and PM2.5-bound PAHs in Huanggang were mainly came from local emissions and relatively short-range transport and the high probability areas were concentrated in Hubei and Henan Province. The total incremental lifetime cancer risks (TILCR) values were ranged from 10−4 to 10−6, indicating the potential cancer risk for adults and children in Huanggang. However, ILCRing and ILCRdem were four orders of magnitude higher than ILCRinh, indicating that ingestion and dermal contact were the main exposure routes for cancer. Vehicle emission contributed the most to TILCR (70.9%), followed by coal and biomass combustion (21.8%) and petroleum sources (7.39%).

The spatial distribution of polycyclic aromatic hydrocarbons (PAHs) and their source contributions employing receptor models has been widely reported. However, the temporal distribution of PAH source contributions is less studied. Thus, in this paper, three receptor models including principle component analysis-multiple linear regression (PCA-MLR), positive matrix factorization (PMF), and Unmix were used to PAH source apportionment study in a sediment core from Honghu Lake, China. Sixteen USEPA priority PAHs in 37 sliced sediment layers (1-cm interval) were measured, with the concentrations of ∑16PAH (sum of 16 PAHs) ranging from 93.0 to 431 ng g−1. The source apportionment results derived from three receptor models were similar, with three common sources: mixed sources of biomass burning and coal combustion (31.0–41.4% on average), petroleum combustion (31.8–45.5%), and oil leakage (13.1–21.3%). The PMF model segregated an additional source: domestic coal combustion (contributed 20.9% to the ∑16PAHs). Four aspects including intra-comparison, inter-comparison, source numbers and compositions, and source contributions were considered in comparison study. The results indicated that the PMF model was most reasonable in PAH source apportionment research in this study.

The paper discussed the distributions, sources and health risk of polycyclic aromatic hydrocarbons (PAHs) in the water-level-fluctuation zone (WLFZ) of the Three Gorges Reservoir (TGR), China, in where the rapid transfer of pollutants between the water and terrene environment cased by the cycle of water fluctuation is of great concern. Twenty-four soil samples were collected in two sampling campaigns, i.e., in September 2012 (the water levels started rising from 145 m) and in June 2013 (the water levels just fell to 145 m), and subsequently they were analyzed for 16 USEPA priority PAHs. Total PAH concentrations (Σ16PAHs) ranged from 18.40 to 392.29 ng·g− 1 (mean 87.66 ng·g− 1) in 2012, and 54.00 to 463.08 ng·g− 1 (mean 133.84 ng·g− 1) in 2013. The concentrations of ΣPAHs in soil sample in 2013 were significantly higher than those in 2012. The concentrations of ΣPAHs in the upstream counties (Banan, Changshou, Fuling and Fengdu) were significantly higher than that in the middle and the lower reaches counties (Zhongxian, Wanzhou, Yunyang, Fengjie, Wushan, Badong, Guizhou and Lanlingxi). The compounds of 3-rings and 4-rings were the major components of PAHs in this area. Individual PAH concentrations were not significantly correlated with total organic carbon (TOC) and microbial biomass carbon (MBC), possibly due to the soil microbial mineralized or degraded PAHs and the semi-continuous inputs from anthropogenesis sources. Source identification indicated that PAHs were mainly derived from river transport and combustion. The incremental lifetime cancer risks ranged from 10− 9 to 10− 6, indicated that the carcinogenic risk for the residents was negligible.

Levels, compositions, sources and health risk of PM2.5-bound PAHs were measured at a regional monitoring site of Huang-gang in the winter of 2018. Samples were collected every morning, afternoon, evening and late night (LN). The average concentrations of PM2.5 and PAHs were 110.4 ± 48.3 µg m–3 and 25.6 ± 12.0 ng m–3, respectively. The concentration of PM2.5 was in the order of evening > morning > afternoon > LN, while PAHs concentration was in the order of evening > LN > morning > afternoon. According to PM2.5 concentration and its changing trend, the haze can be divided into three stages: early (low concentration, January 13–15, EHZ), medium (high concentration, January 16–22, MHZ) and late (concentration decreased rapidly, January 23–24, LHZ). A positive correlation (P < 0.01) was observed between PM2.5 and ∑16PAHs concentration only in MHZ. Besides, PAHs concentration was positively related to NOx concentration, CO concentration and temperature but negatively correlated with RH, independent of O3 concentration. The ratios of OC/EC indicated that the secondary aerosol had a great influence on the formation of haze. Three sources of PAHs including traffic emission, coal combustion and biomass combustion were extracted and quantified, accounting for 54.4%, 13.3% and 32.3% of PAHs, respectively. Potential source contribution function (PSCF) and concentration weighted trajectory (CWT) indicated the transmission of PM2.5 from Wuhan and local pollutant emission were crucial to the formation of haze. BaPeq concentration combined with ILCR values was used to evaluate health risk and the results showed this haze had potential health risk to both adults and children.

Twenty-two street dust samples collected from a small steel city, central China, were analyzed for 16 USEPA priority PAHs to investigate the concentration, spatial distribution relationship with black carbon (BC) and Iron (Fe), and the source apportionment and to assess the health risk of these compounds. The mean contents of PAHs, BC and Fe were 4.43 µg g–1, 12837.97 mg kg–1, 70205.70 mg kg–1, respectively. The highest spot was in the surrounding of the E’zhou Steel Plant and the Steel Rolling Mill of E’zhou. The correlation analysis indicated that there was no obvious relationship between Fe with each other, the PAHs significantly correlated to black carbon (BC), which might be caused by the continuous emission sources of iron and steel production. The results of sources identification suggested that PAHs contaminations in street dust were a mixed source of industrial production and traffic emission combustion. The incremental lifetime and cancer risks (ILCRs) of exposing to PAHs in the street dust of the E’zhou city for the three age groups (namely childhood, adolescence, adulthood) fluctuated with in the range of 10–6 to 10–4, indicating a potential of carcinogenic risk for exposed populations.

Characterization and source identification of PM2.5-bound polycyclic aromatic hydrocarbons (PAHs) are conducted in urban Wuhan (WH), suburban Pingdingshan (PDS), and rural Suizhou (SZ) in China during summer harvest. This study analyzes 16 priority PAHs with 38 PM.2.5 samples in June. PAHs had similar physical-chemical properties like polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs), which had been listed as Priority Pollutants. The concentration and detection frequency of OCPs and PCBs were considerably lower than those of PAHs in PM2.5. Results indicate that PDS adjoining the highway has the highest PM2.5-bound PAHs. SZ possesses the lowest concentration of PAHs. Principal component analysis and multivariate linear regression model and molecular diagnostic ratio distinguish the sources. Vehicle emissions and coal combustion are extracted in three sites, while the source of PDS also includes gas combustion. SZ was affected by gas combustion and petroleum. The potential source contribution function and the concentration-weighted trajectory track the potential pollution area. The sampling places might be affected by the local sources and short distance transmission cannot be neglected. The incremental lifetime cancer risks (ILCRs) model evaluates the exposure risk of PAHs. According to the ILCR model, WH and PDS are exposed to harmful PAHs. By contrast, SZ is a substantially safe place.

The concentrations, spatial distribution, sources and health risks of polycyclic aromatic hydrocarbons (PAHs) and organochlorine pesticides (OCPs) in Dajiuhu Sub-alpine Wetland, central China with totally 38 surface soil samples collected in July 2016 were investigated. The average concentrations were 42.4 ± 38.5 ng·g−1, 7.03 ± 5.59 ng·g−1 and 4.75 ± 5.26 ng·g−1 for Σ15PAHs, HCHs (including α-HCH, β-HCH, γ-HCH, and δ-HCH) and DDTs (including o,p′-DDE, p,p′-DDE, o,p′-DDD, p,p′-DDD, o,p′-DDT, and p,p′-DDT), respectively. In general, the concentrations of POPs in peat soils (71.6 ± 47.9 ng·g−1 for PAHs, 22.9 ± 11.0 ng·g−1 for OCPs) were higher than those in non-peat soils (29.0 ± 23.7 ng·g−1 for PAHs, 6.61 ± 3.06 ng·g−1 for OCPs). The results of molecular diagnostic ratios and principal component analysis (PCA) indicated that PAHs in the study area were mainly originated from petroleum combustion and coal/biomass combustion emission. The relative low ratio of α-/γ-HCH demonstrated that the residual HCHs in surface soils of Dajiuhu were mainly from continuous use of lindane; low ratio of o,p′-DDT/p,p′-DDT was found at most sites, indicating that DDTs were primarily come from historical use of DDTs. The incremental lifetime cancer risks (ILCRs) fluctuated from 10−6 to 10−5 for OCPs and 10−7 to 10−5 for PAHs, which indicated that OCPs and PAHs in the surface soils of Dajiuhu pose a potential cancer risk to local resident.

Heavy metal concentrations and assessment of pollution were carried out in the bottom sediments from Inle Lake, Myanmar analyzed by Inductively Coupled Plasma Mass Spectrometry (ICP- MS). Potential contamination of the sediments was assessed by geo-accumulation (Igeo) index and enrichment factors. The ranges of the metal enrichment in the lake bottom sediments are as follows: Mn > V > Cr > Zn > Ni > Pb > Cu > As > Co > Ga > Sb > Bi> Cd. Based on the results, it can be concluded that lake sediments may be minimal enrichment to moderate enrichment with metals such as Cd, Pb and Bi while moderate enrichment to signifying significant enrichment in sediments by As and Sb. The enrichment factor and geo-accumulation index, revealed that the concentrations of V, Cr, Mn, Co, Ni, Cu, Zn and Ga were mainly influenced by crustal materials or natural weathering processes, while that of metals As, Cd, Pb, Bi and Sb were impacted by the natural and anthropogenic processes. Concentration of As, Cd, Cr, Ni, Pb, Sb and Zn were comparison with Intrime Freshwater Sediment Quality Guidelines (ISQGs). The mean concentrations of elements viz.Cd, Cr, Ni, Pb, Sb and Zn were lower than the threshold effect level (TEL) of ISQGs values except for As. The concentration of As (arsenic) was higher than threshold effect concentration (TEL) value of ISQGs values.

Oil and natural gas are important energy supply around the world. The exploring, drilling, transportation, and processing in oil-gas regions can release abundant volatile organic compounds (VOCs). To understand the atmospheric behaviors of VOCs in such region, the fifty-six VOCs designed as the photochemical precursors by the United State Environmental Protection Agency were continuously measured for an entire year (September 2014–August 2015) by a set of on-line monitor system at an oil-gas station in northwest China. The VOC concentrations in this study were 1–50 times higher than those measured in many other urban and industrial regions. The VOC compositions were also different from other studies with alkanes contributing up to 87.5 % of the total VOCs in this study. According to the propylene-equivalent concentration and maximum incremental reactivity method, alkanes were identified as the most important VOC groups to the ozone formation potential. The photochemical reaction, meteorological parameters (temperature, relative humidity, pressure, and wind speed) and boundary layer height were found to influence the temporal variations of VOCs at different time scales. The positive matrix factorization analysis showed that the natural gas, fuel evaporation, combustion sources, oil refining process, and asphalt contributed 62.6 %, 21.5 %, 10.9 %, 3.8 %, and 1.3 %, respectively to the total VOCs on the annual average. Clear temporal variations differed from one source to another was observed, due to their differences in source emission strength and the influence of meteorological parameters. Potential source contribution function and contribution weighted trajectory models based on backward trajectories indicated that five identified sources had similar geographic origins. Raster analysis based on CWT analysis indicated that the local emissions contributed 48.4 %–74.6 % to the VOCs. This research filled the gaps in understanding the VOCs in the oil-gas field region, where exhibited different source emission behaviors compared with the urban/industrial regions.