Heavy Metals In PM2 Research Articles

Characterisation, Sources and Health Risk of Heavy Metals in PM2.5 in Agra, India

Characterisation, Sources and Health Risk of Heavy Metals in PM2.5 in Agra, India

Transmission characteristics, source apportionment and health risk assessment of PM2.5 in a typical industrial city in Northwest China

To study the source of PM2.5 in Jiayuguan and the effects of heavy metals on human health, from December 2019 to November 2020, 3 sampling points were set up in a background area, commercial area and industrial area in Jiayuguan to collect PM2.5 samples and measure the concentrations of 16 heavy metals. Based on the Meteoinfo and positive matrix factorization (PMF) model, the potential source areas and sources of PM2.5 were determined, and the health risks of heavy metals in PM2.5 to different groups were determined by the EPA health risk assessment method. The results showed that PM2.5 pollution in winter and spring was relatively serious, and the heavy metals with higher concentrations in PM2.5 were Mg, Al, Ca, and Fe. The strong potential source areas were mainly located in the Badain Jaran Desert, Qaidam Basin, Lop Nur area, Hexi Corridor area, and the northern Taklimakan Desert. The sources of heavy metals in PM2.5 included coal combustion, soil dust, cement dust, traffic sources, and industrial sources. The results of the health risk assessment indicated that the heavy metals in local PM2.5 had no significant carcinogenic or noncarcinogenic risks, but the health risks of Cr and Mn should still be considered.

Reproductive toxicity and underlying mechanisms of fine particulate matter (PM2.5) on Caenorhabditis elegans in different seasons

Although numerous studies have investigated that atmospheric fine particulate matter (PM2.5) can be toxic to environmental organisms, the research on the reproductive toxicity of PM2.5 is limited, and the key toxic components and underlying mechanisms remain unknown. In this work, PM2.5 samples of four seasons in Nanjing from March 1, 2021, to February 28, 2022 were collected and the chemical components were analyzed. Caenorhabditis elegans (C. elegans) was employed to conduct the toxicological testing. The reproductive toxicity of PM2.5 to C. elegans in different seasons was evaluated by multiple reproductive endpoints. Exposure to high concentrations of PM2.5 significantly decreased the brood size and the number of fertilized eggs in utero. PM2.5 exposure also increased the number of germ cell corpses and caused abnormal expression of apoptosis-related genes (ced-9, ced-4, and ced-3), which confirmed that PM2.5 induced germline apoptosis. In addition, PM2.5 exposure significantly increased the production of reactive oxygen species (ROS) in C. elegans and the fluorescence intensity of HUS-1 protein in of transgenic strain WS1433. Meanwhile, the expression of genes related to DNA damage (cep-1, clk-2, egl-1, and hus-1) and oxidative stress (mev-1, isp-1, and gas-1) also significantly altered in C. elegans, suggesting induction of DNA damage and oxidative stress. According to Pearson correlation analyses, DNA damage and oxidative stress were significantly correlated with multiple reproductive endpoints in C. elegans. Thus, it was speculated that PM2.5 caused reproductive dysfunction and germ cell apoptosis in C. elegans may be by inducing ROS and DNA damage. In addition, heavy metals in PM2.5 were significantly correlated with multiple endpoints at physiological and biochemical, suggesting that the heavy metals might be an important contributor to the reproductive toxicity induced by PM2.5.

Characterization and Health Risk Assessment of Heavy Metals in PM2.5 in Xiamen Port

PM2.5 samples at Haitian and Songyu container terminals in Xiamen Port were collected in summer and autumn/winter in 2020 and analyzed for 20 elements to investigate their temporal-spatial distribution features, sources, and health risk. The results showed that the levels of PM2.5 were relatively low and did not show significant spatial and diurnal differences. Ca and Si were the main crustal elements, and Zn and Mn were the main heavy metals in PM2.5. Compared with GB 3095-2012 guidelines, Cr(Ⅵ) was in the range of 27.4-28.6 times above the standard. Under the influence of monsoon and port throughput, the concentrations of some elements in summer were higher than those in autumn/winter. Significant diurnal variations were observed for Cu, Zn, SO2, and NO2 but not for V and Ni. Industrial sources were identified as the primary contributor (55.2%-59.4%), followed by traffic (28.7%-31.3%), ship emissions (7.1%-7.7%), and sea salt plus construction dust (4.8%-5.8%). The results of health risk assessment showed that heavy metals in PM2.5in Xiamen Port had potential carcinogenic risk (ECR>1(10-5) to people living near the port, and Cr(Ⅵ), V, and As together accounted for 97.3%-97.5% of the total risks; however, the non-carcinogenic risk was negligible (HI<1), and the major contributors were V, Mn, Ni, and As (89.6%-91.2%). The relative contributions of each contributor to ECR was in the order of traffic (47.2%-49.4%)>industrial (23.8%-24.2%)>ship emissions (16.9%-20.8%)>sea salt plus construction dust (5.7%-12.1%), and the relative contribution to HI was in the order of traffic (38.7%-42.3%)>industrial (24.5%-28.2%)>ship emissions (24.1%-27.2%)>sea salt plus construction dust (5.4%-9.6%).

Concentration Level and Health Risk Assessment of Heavy Metals in PM&lt;sub&gt;2.5&lt;/sub&gt; in Ambient Air of Makkah City, Saudi Arabia

Concentration Level and Health Risk Assessment of Heavy Metals in PM&lt;sub&gt;2.5&lt;/sub&gt; in Ambient Air of Makkah City, Saudi Arabia

The toxicity emissions and spatialized health risks of heavy metals in PM2.5 from biomass fuels burning

The widespread and high use of biomass fuels (BF) by farmers contribute to air pollution-associated health impacts. However, the toxicity and spatial health risks of heavy metals in PM2.5 from BF burning, especially for elements (Cr, As, Cd, Hg, and Pb) listed as hazardous air pollutants (HAPs) in China, remain unknown on the national scale. This study tested the emission factors (EFs) of 18 heavy metals in PM2.5 for 23 BF sources throughout China. Then, complete emission results for heavy metals in PM2.5 from BF burning in China were estimated using the measured EFs and a field survey. Finally, the GEOS-Chem and Risk Quotients models were utilized to calculate the spatialized health risks from heavy metals in PM2.5 for the first time, including the gridded hazard index (HI) and carcinogenic risk (CR). Overall, the measured total EFs of 18 heavy metals in PM2.5 for 23 BF sources ranged from 5.13 mg kg−1 to 24.14 mg kg−1, and the sum EFs of hazardous elements (Cr, As, Cd, Hg, and Pb) varied from 0.45 mg kg−1 to 7.26 mg kg−1. The results indicated that the emissions of Fe, Zn, Pb, Cd, and Cu in PM2.5 from BF burning were the highest, with emissions of 1440.4, 801.8, 434.8, 399.5, and 397.4 Mg, respectively, in 2014. The emissions of other hazardous elements (Cr, As and Hg) in PM2.5 from BF burning were 203.7, 68.67, and 6.36 Mg, respectively. Compared with other anthropogenic sources, the emissions of As (66.7 Mg) from domestic coal burning were similar to those from BF burning, while the emissions of Cr (98.7 Mg) and Cd (102.7 Mg) were much lower for coal. Former studies might have underestimated the toxicity of Cr, As, and Cd by ignoring the emissions from BF burning. Spatially, the hazardous elements exhibited higher emission intensities in the Sichuan Basin, Northeast China Plain, and North China Plain, which exceeded 200, 55, 350, 5 and 350 g yr−1 for Cr, As, Cd, Hg, and Pb, respectively. The monthly emissions of hazardous elements were the highest in winter (January, February, and December), accounting for 41% of the total emissions. On the national scale, the gridded health risk of hazardous elements attributable to BF burning exhibited a relatively high level and spatial heterogeneity. The national HI for children (≤2.8 × 10−2) and adults (≤1.5 × 10−2) were all far lower than the acceptable level (HI ≤ 1). However, the CR in rural areas of Shanxi, Hebei, Beijing, and Henan (1 × 10−6 to 2.7 × 10−6) reached 2.7 times higher than the acceptable level (CR ≤ 1 × 10−6). These results highlighted that when aiming to mitigate the heavy metals exposure risk in the general population, BF burning emissions should be carefully considered. The governments should improve the awareness of the toxicity and health risks from BF burning. which may reduce the willingness of farmers to use BF sources and further promote the rural energy transition and utilization systematically.

Estimations of infiltration factors of diurnal PM2.5 and heavy metals in children's bedrooms.

Children are the sensitive population to fine particulate matter (PM2.5 ) exposure and spend most of their time in bedroom. Infiltration factor (Finf ) can be used to calculate the fraction of total indoor PM2.5 with outdoor origin to increase the accuracy of exposure assessment. However, studies have ignored the diurnal variations of PM2.5 Finf values, and a few studies have estimated Finf values for heavy metals in PM2.5 in children's bedrooms. To calculate the PM2.5 Finf , real-time indoor and outdoor PM2.5 concentrations and occupants' activities were collected in 56 study bedrooms. At 22 of the 56 study bedrooms, PM2.5 samples were also collected for heavy metals analysis. We noted the PM2.5 Finf was higher during the daytime (0.70±0.23) than nighttime (0.54±0.27) during the hot season, and the time of air conditioner use was longer at nighttime. The largest Finf value of heavy metal was V (0.88±0.25), followed by Pb (0.85±0.28), Mn (0.72±0.26), Cr (0.69±0.35), and Zn (0.61±0.32), with a larger variation. Our findings suggest that the estimations of diurnal PM2.5 and heavy metals Finf values are necessary to increase the accuracy of exposure assessment.

Comparison of the Concentrations of Heavy Metals in PM2.5 Analyzed in Three Different Global Research Institutions Using X-ray Fluorescence

This inter-lab study aimed to evaluate the comparability of heavy metal concentrations in the same samples using three X-ray fluorescence spectrometers (XRFs) in three different global re-search institutions, namely a collaboration lab between Soonchunhyang University (Asan, Korea). and PAN (a branch of Malvern PANalytical, Seoul, Korea), RTI (Research Triangle Institute, NC, U.S.A), and Aerosol laboratory in Harvard University, Boston, U.S.A. Indoor air filter samples were collected from 8 homes using 3 filters in each household (n = 24) of individuals with asthma, and the same filter samples were sequentially analyzed separately in the collaboration lab Soonchunhyang-PAN, Harvard University, and RTI. Results showed the detection rates of most heavy metals (n = 25 metals) across the three institutions to be approximately 90%. Of the 25 metals, 16 showed coefficient of determination (R²) 0.7 or higher (10 components had 0.9 or higher) implying high correlation among institutions. Therefore, this study demonstrated XRF as a useful device, ensuring reproducibility and compatibility in the measurement of heavy metals in PM2.5, collected from indoor air filters of asthmatics’ residents.

Heavy metals concentrations and speciation of Pb and Ni in airborne particulate matter over two residential sites in Greater Cairo - reflection from synchrotron radiation.

Synchrotron radiation-based techniques [X-ray absorption near-edge structure (XANES) and X-ray fluorescence (XRF)] combined with inductively coupled plasma-mass spectrometry (ICP-MS) were used for the assessment of heavy metals concentrations as well as lead (Pb) and nickel (Ni) speciation in airborne particulate matter (PM10) over two residential sites in Greater Cairo. Nineteen 24 h high-volume samples collected at Giza (G) Square and Helwan (H) University (Egypt) were selected for this study. Mean concentrations of heavy metals in PM10 at both sites were found to have the same descending order of Pb > Cu > Ni > Cd > Co > As, of which concentrations of Pb, Cu, Ni and Cd in H samples were higher than those in G samples. For Pb, synchrotron-based XRF results were in good agreement with concentrations obtained by ICP-MS. The XANES spectra of PM10 at the Pb L2-edge and Ni K-edge were compared with those of Pb and Ni in model standard compounds to provide information on the potential oxidation states as well as the chemical forms of those elements. The data show that Pb has similar chemical environments in both series G and H with the predominance of Pb2+ oxidation state. Nickel was found as Ni(OH)2, NiO and Ni metal in the analyzed samples. However, the content of Ni in the background filter shows a very strong interference with that of the collected PM10. Carcinogenic and non-carcinogenic risks resulting from the inhalation of the studied heavy metals were assessed for children and adult residents and were found below the safe limits, at both sites.

Pollution Characterization, Source Identification, and Health Risks of Atmospheric Particle-Bound Heavy Metals in PM2.5 in Zhengzhou City: Based on High-resolution Data

In order to study the pollution characteristics and sources of heavy metals in urban atmospheric PM2.5, 21 elements in atmospheric PM2.5 in Zhengzhou City were detected using an online metal analyzer during July and October 2017 and January and April 2018, and the changes in heavy metal concentrations were analyzed. Heavy metals were traced by enrichment factors, principal component analysis, and potential source function. The US EPA risk assessment model was used to assess their health risks. The results showed that:the concentrations of K, Zn, Mn, Pb, Cu, As, Cr, and Se increased with the increase in pollution level. The results of enrichment factors and principal component analysis showed that the main sources of heavy metals were crust, mixed combustion, industry, and motor vehicles. The characteristic radar charts showed that the pollution dominated by crustal sources mainly occurred in spring and winter, whereas the pollution dominated by mixed combustion sources mainly occurred in winter. Pb, As, and Ni were greatly affected by the transport of a fen nutrient-laden plain, Beijing-Tianjin-Hebei, and southern Henan, whereas Cd was greatly affected by the northwest region of the sampling site. As presented a significant carcinogenic risk in both adults and children, whereas Pb and Sb presented a significant non-carcinogenic risk in children.

Contribution of heavy metals in PM2.5 to cardiovascular disease mortality risk, a case study in Guangzhou, China

Heavy metals play an important role in inducing fine particulate matter (PM2.5) related cardiovascular disease (CVD). However, most of the past researches concerned the associations between CVD mortality and the PM2.5 mass, which may not reveal the CVD mortality risk contributed by heavy metals in PM2.5. This study explored the correlations between individual heavy metals in PM2.5 and CVD mortality, identified the heavy metals that significantly contribute to PM2.5-related CVD, heart disease (HD), and cerebrovascular disease (CEV) mortality, and attempted to establish corresponding source control measures. Over a 2-year study period, PM2.5 was sampled daily in Guangzhou, China and analyzed for heavy metals. The airborne pollution and weather data, along with CVD, HD, and CEV mortality, were obtained at the same time. The excess risk (ER) of mortality was linked to the individual heavy metals using a distributed lag non-linear model. PM2.5 and most heavy metals showed significant correlations with the CVD, HD, and CEV mortality; the largest cumulative ER (LCER) values of CVD mortality associated with an interquartile range increase in the levels of lead, cadmium, arsenic, selenium, antimony, nickel, thallium, aluminum, iron, and PM2.5 were 2.43%, 2.23%, 1.66%, 2.39%, 1.19%, 1.21%, 2.69%, 3.29%, 1.74%, and 2.40%, respectively. Most heavy metals showed comparable LCER values of HD and CEV mortality. Heavy metals with the addition of PM2.5 were divided into three groups following their LCER values; lead, cadmium, arsenic, antimony, thallium, zinc, aluminum, and iron, whose contributions were greater than or equal to the average effect of the PM2.5 components, should be limited on a priority basis. These findings indicated that heavy metals play roles in the CVD, HD, and CEV mortality risk of PM2.5, and specific control measures which aimed at the emission sources should be taken to reduce the CVD mortality risk of PM2.5.

Pollution Characteristics and Health Risk of Heavy Metals in Fugitive Dust Around Zhaotong City

In order to explore the pollution characteristics and health risks of heavy metals in fugitive dust around the urban areas of Zhaotong City, road dust and soil dust samples were collected in the Zhaoyang District of Zhaotong City in May 2019. The dust samples were suspended using a particle resuspension system to obtain PM2.5 (particulate matter with an aerodynamic diameter less than or equal to 2.5 μm). The concentrations of Ca, Al, Fe, Mg, Ti, V, Cr, Mn, Co, Ni, Cu, Zn, As, Cd, and Pb in PM2.5 were quantified by ICP-MS and ICP-OES. By analyzing 10 types of heavy metals in PM2.5, the results showed that the average concentration of Mn was the highest in the soil fugitive dust, followed by Cr, Ni, Zn, Cu, Co, Pb, V, As, and Cd. The average concentration of Zn in the road fugitive dust was the highest, followed by Mn, Cu, Cr, Pb, Ni, As, Co, V, and Cd. The enrichment factor (EF) indicated that Cd was strongly enriched in the two types of fugitive dust. The EFs of Cu, Zn, and Pb in road fugitive dust showed a moderate enrichment, and they were higher than those in soil fugitive dust. Correlation and principal component analysis showed that heavy metals in the two types of fugitive dust were affected by coal burning sources. At the same time, heavy metals in soil fugitive dust were affected by agricultural activity sources, and heavy metals in road fugitive dust were affected by traffic sources. The results of the health risk assessment indicated that the carcinogenic risks of Cr, Co, Ni, As, and Cd in soil fugitive dust were higher than those in road fugitive dust. The non-carcinogenic risks of heavy metals in the two types of fugitive dust for children were higher than those for adults, and the non-carcinogenic risks of Cu, Zn, and Pb in road fugitive dust were higher than those in soil fugitive dust.

Pollution Characteristics and Health Risk Assessment of Heavy Metals in PM&amp;lt;sub&amp;gt;2.5&amp;lt;/sub&amp;gt; during Winter in the Suburb of Cangzhou, China

The heavy metals in atmospheric fine particles are of great concern to human health. To understand the pollution characteristics and health risks of heavy metals in particulate matter with an aerodynamic equivalent diameter ≤2.5 μm (PM2.5) during winter in the suburb of Cangzhou, PM2.5 samples were collected with an intelligent medium-flow atmospheric particulate matter sampler from January to February 2019. The Fe, Cu, Mn, Pb and Zn contents in PM2.5 were determined via inductively coupled plasma optical emission spectrometry (ICP-OES). The sources and health risks of heavy metals in PM2.5 were analysed via the enrichment factor (EF) method and the United States Environmental Protection Agency (US EPA) health risk assessment model. The results showed that the average PM2.5 concentration in the suburb of Cangzhou reached 71.6 μg/m3, ranging from 23.7 to 169.5 μg/m3. The exceeding standard rate was 29.4% during the sampling period. The PM2.5 concentration during the nighttime was higher than that during the daytime. The heavy metal concentrations in PM2.5 decreased in the order of Fe > Mn > Zn > Cu > Pb, and the Fe, Mn, Pb and Zn concentrations decreased in the order of clean days the daytime. EF analysis revealed that Zn, Pb and Cu were significantly enriched, and Pb was highly enriched on heavy pollution days with increasing pollution degree. The enrichment level of heavy metals during the nighttime was higher than that during the daytime. Health risk assessment demonstrated that Mn posed non-carcinogenic risks to both adults and children, following the sequence of clean days . The study revealed that the pollution levels of heavy metals in PM2.5 in the suburb of Cangzhou were low, and Pb and Mn in PM2.5 posed certain health risks to the population.

Source Apportionment and Risk Estimation of Heavy Metals in PM10 at a Southern Vietnam Megacity

Airborne particulate matter (PM) pollution is a global concern, in which partitioned heavy metals (HMs) could impose great risks to residents living in metropolitan areas. In this study, PM10 samples were collected in Ho Chi Minh City (HCMC) – a megacity in southern Vietnam – and analyzed for 11 HMs to investigate their concentration profiles, perform source apportionment and estimate their risk factors. Results showed that atmospheric HMs concentration decreased following the order of Al > Fe > Sr > Mn> Pb > Cu > Cr > V > Ni > Sb > As. Traffic activities were likely the major cause of rush-hour peaks for most HMs in which Cr, As, and Cu showed > 20% increases in their relative proportions. For seasonal variation, most HMs showed a dry > rainy pattern as a result of washout by higher rainfall in the rainy season while crustal elements (Al, Sr, Mn) showed a rainy > dry pattern and might be explained by the difference in air mass transport modulating by monsoon activities. The positive-matrix factorization (PMF) model revealed 5 primary sources for HMs, including traffic emission, shipping activity and combustion activity, fugitive dust re-suspension and waste incineration. Combustion activity might enrich As, Sb, Pb levels at HCMC, and As contributed half (50.8%) to the potential ecological risk (PER) in the city. Besides, the current Cr level could impose a carcinogenic effect towards children in HCMC (total carcinogenic index > 10-4) while Mn might impose intolerable non-carcinogenic risk (hazard index > 1). This study provides information on local air quality status for scientific and regulatory perspectives as well as helps fill the information gap and update the understanding of air pollution in South and Southeast Asia.

Composition, sources, and health risk assessment of particulate matter at two different elevations in Delhi city

The PM10 and PM2.5 source apportionment and health risk assessment were performed for two different elevations (lower elevation (LE) ∼5–10 m and higher elevation (HE) ∼30–45 m) at four different locations of Delhi city during January 2017–March 2017. The measured 24-h average PM10 and PM2.5 concentrations at different locations were found between 134.7 and 257.7 μg/m3 and 78.7–121.1 μg/m3, respectively. The 24-h average PM10 and PM2.5 concentrations at the study sites were exceeding the national (NAAQS) and WHO limits by more than 1.3 and 3 times, respectively. The PM mass was enriched with carbonaceous matter, ions, crustal and trace elements and their concentrations (except, Sr, Ni, S, As, V, Sb, Ga- the trace elements associated with coal and heavy oil combustion & NO3− - due to high nitrate formation ability at greater heights) were found higher in LE. The source apportionment study was performed with positive matrix factorisation (PMF). PMF analysis identified vehicular emission (PM10, 9.6–24.3% & PM2.5, 12.1–25.3%), secondary inorganics (PM10, 6.4–22.5% & PM2.5, 11–23%), crustal source (PM10, 9–52% & PM2.5, 3.8–10.7%), fuel oil combustion (PM10, 3–21% & PM2.5, 9–23%), biomass burning (PM10, 7.4–28.6% & PM2.5, 6–50.5%), and coal combustion (PM10, 13–17% & PM2.5, 14–19.1%) as the main sources of PM10 and PM2.5 at the study sites. A significant difference in source contribution between the elevations was observed for coal combustion, fuel oil combustion, biomass burning, and crustal sources. The contribution of vehicular emission and secondary inorganics estimates were broadly similar at both elevations. Coal and fuel oil combustion contribution was found relatively higher at HE. Further, health risk due to exposure to toxic heavy metals in PM2.5 was assessed. Non-carcinogenic and carcinogenic risks (averaged of four sites) for both children and adults were exceeding the acceptable limit by more than 1.13 times. Results also showed that the public residing at HE is more susceptible to have greater health risks than LE at Delhi city. Sources contribution to carcinogenic risk was assessed and the results indicated that coal combustion (41%) contribution was highest followed by crustal sources (22%), fuel oil combustion (17%), vehicular emission (12%), biomass burning (4%) and secondary inorganics (4%).

Concentrations of heavy metals in PM2.5 and health risk assessment around Chinese New Year in Dalian, China

Abstract Twelve samples of heavy metals were analyzed by using a 1108A-1 mid-current particle sampler in Dalian, Liaoning Province, for 31 days before and after the spring festival 2019. The results showed that the concentrations of heavy metals were decreased by more than 25% during the spring festival, which was probably due to the shutdown of the factories and the decrease in people’s travel. During the spring festival, the concentration of Ba was increased by 343.39% as compared to the concentration of Ba before the spring festival, which indicated that the fireworks had a great influence on the concentration of Ba. At the same time, this study also evaluated the health risk of heavy metals. For the heavy metals As, Cd, Co, Cr, and Ni, the lifetime cancer risk was found to be 2.13 × 10−4, 2.08 × 10−5, 8.64 × 10−7, 4.39 × 10−4 and 7.93 × 10−7, respectively. The lifetime cancer risk of As, Cd, and Cr exceeds the threshold range of cancer risk (10−6–10−4), indicating that they are carcinogenic to humans. Also, during the spring festival, the non-carcinogenic risk value of V exceeded the limit value of environmental protection agency (EPA), and the lifetime carcinogenic risk value of As, Cd, and Cr exceeded the threshold range of carcinogenic risk; hence, they need to be carefully monitored and controlled.

Concentrations, Source Characteristics, and Health Risk Assessment of Toxic Heavy Metals in PM2.5 in a Plateau City (Kunming) in Southwest China.

To explore the mass concentration levels and health risks of heavy metals in the air in dense traffic environments, PM2.5 samples were collected at three sites in the city of Kunming in April and October 2013, and January and May 2014. Ten heavy metals––V, Cr, Mn, Co, Ni, Cu, Zn, As, Cd and Pb––were analyzed by ICP–MS, and the results showed PM2.5 concentrations significantly higher in spring and winter than in summer and autumn, especially for Zn and Pb. The concentration of heavy metals on working days is significantly higher, indicating that vehicle emissions are significant contributors. An enrichment factor analysis showed that Cr, Mn, Ni, Cu, Zn, As, Cd and Pb come mainly from anthropogenic sources, while V and Co may be both anthropogenic and natural. The correlation and principal component analysis (PCA) showed that Ni, Cu, Zn, Cd and Pb mainly come from vehicles emissions and metallurgical industries; Cr and Mn, from vehicles emissions and road dust; and As, mainly from coal combustion. The health risk assessment shows that the non-carcinogenic risk thresholds of the heavy metals in PM2.5 to children and adult men and women are all less than 1. The carcinogenic risk of Cr for men and women in traffic-intensive areas exceeds 10−4, reaching 1.64 × 10−4 and 1.4 × 10−4, respectively.

The heavy metals in indoor and outdoor PM2.5 from coal-fired and non-coal-fired area

To compare the pollution characteristics and sources of heavy metal in indoor and outdoor PM2.5 from coal-fired and non-coal-fired area in winter of Qian'an City, PM2.5 samples were collected in January 2016. The methods of EF and PCA were used to discuss the sources of heavy metal in PM2.5. The results showed that the average concentration indoor and outdoor PM2.5 were 128.45 and 46.27 μg/m3) in coal-fired area, 66.64 and 29.82 μg/m3 in non-coal-fired area. The ratio of I/O was more than one for Cr, Cu, Zn, Cd and Pb, and lower one for Ni indoor and outdoor environment. Indoor sources were more contributed to Cr in coal-fired area. About 4% of Ni, 40% Cu, 64% Zn, 62% Cd, 54% Pb entered indoor from outdoor for coal-fired area. The 11% of Ni entered indoor from outdoor for non-coal-fired area. EF and PCA method indicated that coal combustion and metal smelting was main contributor for indoor PM2.5, however metal smelting was main sources for outdoor PM2.5. The present study suggested that the central heating and industry reduction would effectively improve indoor air quality in rural-urban fringe zone.

Characteristics and Health Risk Assessment of Heavy Metals in PM2.5 Under Winter Haze Conditions in Central China: A Case Study of Huanggang, Hubei Province

To explore the pollution characteristics and potential health risks of heavy metals in PM2.5 on haze days in Central China, PM2.5 samples were collected from the Huanggang monitoring station, a regional observation point in Central China, between January 13 and 24, 2018. The contents of Cr, Mn, Co, Ni, Cu, Zn, As, Cd, Sn, and Pb in PM2.5 were analyzed by inductively coupled plasma mass spectrometry(ICP-MS), and the enrichment factor method was used to determine the potential risk based on the exposure model recommended by the Environmental Protection Administration(EPA). The results showed that during the observation period, the concentrations of Zn in PM2.5 were highest, and the concentrations of the carcinogens As and Cd were higher than the secondary standard limits of China's ambient air quality standard(GB 3095-2012), with 70% of these elemental concentrations accounting for the largest proportion in the middle haze period. The enrichment factor analysis showed that Cd, Sn, Co, Pb, and Zn were the most abundant elements, especially during the middle haze period, and were mostly derived from transportation and coal combustion. The results of the human health risk assessment showed that exposure via hand-mouth feeding was the main non-carcinogenic risk, and the exposure and non-carcinogenic risks of children were significantly higher than those of adults. Pb poses a non-carcinogenic risk to children, while heavy metals in PM2.5 pose no non-carcinogenic risks to adults and carcinogenic heavy metals pose no carcinogenic risks.

Source Apportionment and Health Risk Assessment of Heavy Metals in PM2.5 in Handan: A Typical Heavily Polluted City in North China

In order to determine the pollution sources and human health risks of metal elements in PM2.5, samples were collected by a large flow particulate matter sampler in the four seasons in 2013, 2015, and 2017 (January, April, July, and October). The mass concentrations of 10 metals (Ti, V, Cr, Mn, Ni, Cu, Zn, As, Cd, and Pb) were analyzed. The sources of heavy metals were identified by Unmix, and the potential non-carcinogenic/carcinogenic risk was evaluated. The influences of local and regional sources were also explored during the high-carcinogenic risk period (HCRP). The wind field and 72 h backward trajectories were performed to identify the potential local and regional sources in HCRP. The results showed that the average annual concentrations of PM2.5 in the urban area of Handan city were 105.14, 91.18, and 65.85 μg/m3 in 2013, 2015, and 2017, respectively. The average daily concentrations of the metals in PM2.5 in January were higher than that of April, July, and October. The average mass concentrations of the 10 heavy metal elements in PM2.5 were 698.26, 486.92, and 456.94 ng·m−3 in 2013, 2015, and 2017, respectively. The main sources of the metals in PM2.5 were soil dust sources, vehicular emissions, coal burning, and industrial activities. The carcinogenic risks of Cr and As were above 1 × 10−6 over the three years. Wind direction analysis showed that the potential local sources were heavy industry enterprises and the economic development zone. The backward trajectory analysis indicated that PM2.5 long transported from Shandong, Henan, and the surrounding cities of Handan had quite an impact on the heavy metals contained in the atmosphere of the studied area. The health risk assessment results demonstrated that the trend for non-carcinogenic risk declined, and there was no non-carcinogenic risk in 2017. However, the carcinogenic risk levels were high over the three years, particularly in January.