Metals In PM2 Research Articles

CRISPR/Cas9-Mediated Whole Genomic Wide Knockout Screening Identifies Specific Genes Associated With PM2.5-Induced Mineral Absorption in Liver Toxicity.

PM2.5, also known as fine particles, refers to particulate matter with a dynamic diameter of ≦2.5 μm in air pollutants, that carries metals (Zn, Co, Cd) which can pass through the alveolar epithelium and enter the circulatory system and tissues. PM2.5 can cause serious health problems, such as non-alcoholic fatty liver and hepatocellular carcinoma, although the underlying mechanisms of its toxic effect are poorly understood. Here, we exposed L02 cells to PM2.5 and performed a pooled genome−wide clustered regularly interspaced short palindromic repeats/CRISPR-associated protein 9 (CRISPR/Cas9) to assess loss of function and identify new potential PM2.5targets. Enrichr and KEGG pathway analyses were performed to identify candidate genes associated with PM2.5 toxicity. Results revealed that four key genes, namely ATPase Na+/K+ transporting subunit alpha 2 (ATP1A2), metallothionein 1M (MT1M), solute carrier family 6 members 19 (SLC6A19) and transient receptor potential cation channel subfamily V member 6 (TRPV6) were associated with PM2.5 toxicity, mainly in regulating the mineral absorption pathway. Downregulating these genes increased cell viability and attenuated apoptosis in cells exposed to PM2.5. Conversely, overexpressing TRPV6 exacerbated cell apoptosis caused by PM2.5, while a reactive oxygen species (ROS) inhibitor N-acetyl-l-cysteine (NAC) alleviated PM2.5-induced apoptosis. In conclusion, ATP1A2, MT1M, SLC6A19 and TRPV6 may be contributing to absorption of metals in PM2.5 thereby inducing apoptosis mediated by ROS. Therefore, they hold potential as therapeutic targets for PM2.5-related diseases.

Effect of Different Pollution Parameters and Chemical Components of PM2.5 on Health of Residents of Xinxiang City, China.

The present study was planned to explore the pollution characteristics, health risks, and influence of atmospheric fine particulate matter (PM2.5) and its components on blood routine parameters in a typical industrial city (Xinxiang City) in China. In this study, 102 effective samples 28 (April–May), 19 (July–August), 27 (September–October), 28 (December–January) of PM2.5 were collected during different seasons from 2017 to 2018. The water-soluble ions and metal elements in PM2.5 were analyzed via ion chromatography and inductively coupled plasma–mass spectrometry. The blood routine physical examination parameters under different polluted weather conditions from January to December 2017 and 2018, the corresponding PM2.5 concentration, temperature, and relative humidity during the same period were collected from Second People’s Hospital of Xinxiang during 2017–2018. Risk assessment was carried out using the generalized additive time series model (GAM). It was used to analyze the influence of PM2.5 concentration and its components on blood routine indicators of the physical examination population. The “mgcv” package in R.3.5.3 statistical software was used for modeling and analysis and used to perform nonparametric smoothing on meteorological indicators such as temperature and humidity. When Akaike’s information criterion (AIC) value is the smallest, the goodness of fit of the model is the highest. Additionally, the US EPA exposure model was used to evaluate the health risks caused by different heavy metals in PM2.5 to the human body through the respiratory pathway, including carcinogenic risk and non-carcinogenic risk. The result showed that the air particulate matter and its chemical components in Xinxiang City were higher in winter as compared to other seasons with an overall trend of winter > spring > autumn > summer. The content of nitrate (NO3−) and sulfate (SO42−) ions in the atmosphere were higher in winter, which, together with ammonium, constitute the main components of water-soluble ions in PM2.5 in Xinxiang City. Source analysis reported that mobile pollution sources (coal combustion emissions, automobile exhaust emissions, and industrial emissions) in Xinxiang City during the winter season contributed more to atmospheric pollution as compared to fixed sources. The results of the risk assessment showed that the non-carcinogenic health risk of heavy metals in fine particulate matter is acceptable to the human body, while among the carcinogenic elements, the order of lifetime carcinogenic risk is arsenic (As) > chromium(Cr) > cadmium (Cd) > cobalt(Co) > nickel (Ni). During periods of haze pollution, the exposure concentration of PM2.5 has a certain lag effect on blood routine parameters. On the day when haze pollution occurs, when the daily average concentration of PM2.5 rises by 10 μg·m−3, hemoglobin (HGB) and platelet count (PLT) increase, respectively, by 9.923% (95% CI, 8.741–11.264) and 0.068% (95% CI, 0.067–0.069). GAM model analysis predicted the maximum effect of PM2.5 exposure concentration on red blood cell count (RBC) and PLT was reached when the hysteresis accumulates for 1d (Lag0). The maximum effect of exposure concentration ofPM2.5 on MONO is reached when the lag accumulation is 3d (Lag2). When the hysteresis accumulates for 6d (Lag5), the exposure concentration of PM2.5 has the greatest effect on HGB. The maximum cumulative effect of PM2.5 on neutrophil count (NEUT) and lymphocyte (LMY) was strongest when the lag was 2d (Lag1). During periods of moderate to severe pollution, the concentration of water-soluble ions and heavy metal elements in PM2.5 increases significantly and has a significant correlation with some blood routine indicators.

A review on the effect of air pollution and exposure to PM, NO2 , O3 , SO2 , CO and heavy metals on viral respiratory infections

The ambient air pollutants that have a major role in causing respiratory diseases are particulate matter, sulfur dioxide, nitrogen dioxide, ozone, carbon monoxide, and heavy metals. In addition, respiratory infections, divided into upper respiratory tract and lower respiratory tract infection, are most commonly caused by viral agents. Thus, in light of the current COVID-19 pandemic, this review has focused on the association between exposure to general air pollution including each of the mentioned air pollutants and viral respiratory infections. The gathered evidence from the reviewed studies in this article showed that most of these air pollutants have a positive correlation with mortality, severity, transmission, inflammation, and incidence of different viral respiratory infections. Whereas, some studies found contradictory results such as non-significant and negative connections between exposure to air pollutants and viral respiratory infections, which are further discussed in this text. Therefore, following the SARS-CoV-2 outbreak, these contradictions in the reported correlation between air pollution and different aspects of viral respiratory infections must be thoroughly investigated and cleared.

Seasonal variations and risk assessment of heavy metals in PM2.5 from Handan, China

Purpose This study aims to acquire a better understanding on the characteristics and risks of heavy metals (HMs) in PM2.5 from an industrial city – Handan, China. Design/methodology/approach PM2.5 samples were collected on the basis of daytime and nighttime at the state controlling air sampling site in Handan city. Ten metal elements (V, Cr, Mn, Fe, Ni, Cu, Rb, Sr, Cd and Ba) in PM2.5 were determined with an inductively coupled plasma mass spectrometry. The pollution levels of metals were characterized by enrichment factors, and the sources of metals were identified with principle component analysis and cluster analysis. The ecological and health risks of metals were assessed using ecological and health risk indexes. Findings Results showed that the highest and lowest PM2.5 concentration appeared in winter and summer, respectively. The concentration of PM2.5 at night was higher than in the daytime in winter, yet it is the opposite in other seasons. The total mass concentration of detected metals was the highest in winter, and the total mass concentration in the daytime was higher than at night in all four seasons. The elements V, Rb, Sr and Ba exhibited a deficient contamination level; Cr, Ni and Cu exhibited a moderate contamination level; while Fe and Cd were at an extreme contamination level. The metals in PM2.5 originated from a mixture source of fossil fuel combustion and manufacture and use of metallic substances (34.04%), natural source (26.01%) and construction and traffic-related road dust (17.58%). Results from the ecological risk model showed that the ecological risk of metals was very high, especially risks related to Cd. Health risk model presented that both the non-carcinogenic and carcinogenic risk coefficients of metals were above the tolerance level of the human body. Originality/value The significance of the study is to further know the pollution characteristics of PM2.5 and related HMs in Handan city, and to provide references for ensuring local resident health and ecological environment.

Loss of E-cadherin due to road dust PM2.5 activates the EGFR in human pharyngeal epithelial cells.

Exposure to road dust particulate matter (PM) causes adverse health impacts on the human airway. However, the effects of road dust on the upper airway epithelium in humans remain unclear. We investigated the involvement of the epidermal growth factor receptor (EGFR) after PM with an aerodynamic diameter of < 2.5 μm (PM2.5)-induced E-cadherin disruption of human pharyngeal epithelial cells. First, we collected road dust PM2.5 from 10 Chinese cities, including Wuhan, Nanjing, Shanghai, Guangzhou, Chengdu, Beijing, Lanzhou, Tianjin, Harbin, and Xi'an. Human pharyngeal FaDu cells were exposed to road dust PM2.5 at 50 μg/mL for 24 h, cytotoxicity (cell viability and lactate dehydrogenase (LDH)) was assessed, and expressions of the proinflammatory interleukin (IL)-6 and high-mobility group box 1 (HMGB1) protein, receptor for advanced glycation end products (RAGE), occludin, E-cadherin, EGFR, and phosphorylated (p)-EGFR were determined. The E-cadherin gene was then knocked down to investigate EGFR activation in FaDu cells. Exposure to road dust PM2.5 resulted in a decrease in cell viability and increases in LDH and IL-6. Our data suggested that PM2.5 could decrease expressions of occludin and E-cadherin and increase expressions of EGFR and p-EGFR, which was confirmed by E-cadherin-knockdown. Our results showed a negative association between the alterations in E-cadherin and total elemental components in correlation analysis, especially S, Cl, K, Ti, Mn, Fe, Cu, Zn, and Pb. Exposure to metals in PM2.5 from road dust may lead to loss of the barrier function of the upper airway epithelium and activation of the EGFR. Our study showed the adverse effects of road dust PM2.5 on pharyngeal epithelial cells of the human upper airway.

Size-segregated chemical source profiles and potential health impacts of multiple sources of fugitive dust in and around Bhopal, central India

PM2.5 and PM10 fugitive dust samples from multiple sources (construction, demolition, industrial, agricultural fields, and bare ground) were collected in triplicate for each size bin, from 18 distinct locations in and around Bhopal, central India. The dust samples were dried, sieved, and re-suspended in a chamber fitted with a suitable sampling system, to collect PM2.5 and PM10 samples onto Teflon and Quartz filters. The filters were subjected to gravimetric and chemical analyses. Trace elements, water-soluble ions, and thermal-optical carbon fractions were quantified using a variety of analyses. These species were then used to develop PM10 and PM2.5 chemical source profiles of the fugitive dust sources. As expected, crustal species were abundant in all source categories. For industrial dust, Fe contribution to mass in both size fractions was about 11.4% and above the upper continental crustal abundance. Further, the source profiles generated for each source were different from their counterparts in the US EPA SPECIATE database and profiles reported in literature. Thus, it will be useful to utilize profiles generated in this study to enhance receptor model performance for the study region. However, collinearity analysis of the profiles revealed that PM10 agricultural and bare ground dust; and PM2.5 construction and demolition dust profile pairs may not be separated by receptor models. Finally, a human health risk assessment revealed that construction and industrial dust may pose significant risk to the population. The Incremental Lifetime Cancer Risk (ILCR) metric revealed that adults (2 × 10−5) and children (1 × 10−5) were susceptible to cancer risk from exposure to metals in PM2.5 fugitive dust. Further, children were more vulnerable than adults. This finding merits further investigation of oxidation state and solubility/bioavailability of Cr and Ni in fugitive dusts.

Susceptibility of patients with chronic obstructive pulmonary disease to heart rate difference associated with the short-term exposure to metals in ambient fine particles: A panel study in Beijing, China.

Susceptibility of patients with chronic obstructive pulmonary disease (COPD) to cardiovascular autonomic dysfunction associated with exposure to metals in ambient fine particles (PM2.5, particulate matter with aerodynamic diameter ≤2.5 µm) remains poorly evidenced. Based on the COPDB (COPD in Beijing) panel study, we aimed to compare the associations of heart rate (HR, an indicator of cardiovascular autonomic function) and exposure to metals in PM2.5 between 53 patients with COPD and 82 healthy controls by using linear mixed-effects models. In all participants, the HR levels were significantly associated with interquartile range increases in the average concentrations of Cr, Zn, and Pb, but the strength of the associations differed by exposure time (from 1.4% for an average 9 days (d) Cr exposure to 3.5% for an average 9 d Zn exposure). HR was positively associated with the average concentrations of PM2.5 and certain metals only in patients with COPD. Associations between HR and exposure to PM2.5, K, Cr, Mn, Ni, Cu, Zn, As, and Se in patients with COPD significantly differed from those in health controls. Furthermore, association between HR and Cr exposure was robust in COPD patients. In conclusion, our findings indicate that COPD could exacerbate difference in HR following exposure to metals in PM2.5.

Tracing local sources and long-range transport of PM10 in central Taiwan by using chemical characteristics and Pb isotope ratios

Central Taiwan is among the most heavily polluted regions in Taiwan because of a complex mixing of local emissions from intense anthropogenic activities with natural dust. Long-range transport (LRT) of pollutants from outside Taiwan also contributes critically to the deterioration of air quality, especially during the northeast monsoon season. To identify the sources of particulate matter < 10 μm (PM10) in central Taiwan, this study performed several sampling campaigns, including three local events, one LRT event, and one dust storm event, during the northeast monsoon season of 2018/2019. The PM10 samples were analyzed for water-soluble ion and trace metal concentrations as well as Pb isotope ratios. Local sediments were also collected and analyzed to constrain chemical/isotopic signatures of natural sources. The Pb isotope data were interpreted together with the enrichment factors and elemental ratios of trace metals in PM10, and reanalysis data sets were used to delineate the sources of PM10 in central Taiwan. Our results suggested that Pb in PM10 was predominantly contributed by oil combustion and oil refineries during the local events (48–88%), whereas the lowest contributions were from coal combustion (< 21%). During periods of high wind speed, the contribution from natural sources increased significantly from 13 to 31%. Despite Pb represented only a small portion of PM10, a strong correlation (r = 0.89, p < 0.001, multiple regression analysis) between PM10 mass and the concentrations of Pb, V, and Al was observed in the study area, suggesting that the sources of PM10 in central Taiwan can be possibly tracked by using chemical characteristics and Pb isotopes in PM10. Moreover, the Pb isotopic signals of PM10 collected during the LRT event confirmed the impact of LRT from Mainland China, and the chemical characteristics of the PM10 significantly differed from those of the PM10 collected during local events. This study demonstrates the robustness of using a combination of Pb isotopic compositions and chemical characteristics in PM10 for source tracing in complex and heavily polluted areas.

Particulate Matter and Associated Metals: A Link with Neurotoxicity and Mental Health

Particulate air pollution (PM) is a mixture of heterogenous components from natural and anthropogenic sources and contributes to a variety of serious illnesses, including neurological and behavioral effects, as well as millions of premature deaths. Ultrafine (PM0.1) and fine-size ambient particles (PM2.5) can enter the circulatory system and cross the blood–brain barrier or enter through the optic nerve, and then upregulate inflammatory markers and increase reactive oxygen species (ROS) in the brain. Toxic and neurotoxic metals such as manganese (Mn), zinc (Zn), lead (Pb), copper (Cu), nickel (Ni), and barium (Ba) can adsorb to the PM surface and potentially contribute to the neurotoxic effects associated with PM exposure. Epidemiological studies have shown a negative relationship between exposure to PM-associated Mn and neurodevelopment amongst children, as well as impaired dexterity in the elderly. Inhaled PM-associated Cu has also been shown to impair motor performance and alter basal ganglia in schoolchildren. This paper provides a brief review of the epidemiological and toxicological studies published over the last five years concerning inhaled PM, PM-relevant metals, neurobiology, and mental health outcomes. Given the growing interest in mental health and the fact that 91% of the world’s population is considered to be exposed to unhealthy air, more research on PM and PM-associated metals and neurological health is needed for future policy decisions and strategic interventions to prevent public harm.

Bioaccessibility and source-specific health risk of heavy metals in PM2.5 in a coastal city in China

Heavy metals in PM2.5 (a global pollutant) are bio-accessible and highly toxic. Health risk assessment of bioaccessible heavy metals in PM2.5 was analyzed in the present study to relate the bioaccessibility with health outcomes. Then source-specific health risk was used to find out the major health abuser, which could provide reliable evidence for accurate pollution control. PM2.5 samples were collected in four seasons included spring, summer, autumn, and winter in urban and suburban areas in Xiamen, China. The order of heavy metals’ concentrations in PM2.5 was Cu > Zn > Mn > Ni > Pb> V > Co > Cr, urban area > suburb. Heavy metals in PM2.5 were mainly from anthropogenic sources that contributed more than 69.30%, 56.51%, 69.70%, 58.99% in spring, summer, autumn, and winter, respectively. Bioaccessibility of V, Pb, and Zn was relatively high, Co, Ni, Mn was relatively low after extracting by an artificial lysosomal fluid at pH=4.5. Bioaccessibility of Cr in spring and summer was higher than that in autumn and winter (60.4%–90.7% vs. 16.1%–69.2%) due to different sources and species in various seasons. Bioaccessibility of Cu after 1 d extraction was higher than that after 15 d extraction (69.6%–78.4% vs. 33.8%–48.2%) because of reverse adsorption of filter membranes and particulate matter. Health risks of bioaccessible heavy metals were lower than those of total heavy metals. However, both total and bioaccessible Cr and Cd had carcinogenic risks. Based on the combined positive matrix factorization-health risk (PMF-HR) model, industry, combustion, and traffic emission contributed the most to the health risk of Cr and Cd, followed by soil parent material layer. Our study provided a reliable method to calculate the bioaccessible heavy metal health risk and determine each potential source's contribution to health risk.

Indoor particulate matter and blood heavy metals in housewives: A repeated measured study

BackgroundParticulate matter (PM) less than 2.5 μm in diameter and 10 μm (PM10) contains heavy metals, but whether exposure to PM is significantly associated with the burden of heavy metal exposure in the population is unknown. We investigated the association between exposure to PM and blood concentrations of lead (Pb), cadmium (Cd), and mercury (Hg) in Korean housewives. Materials & MethodsFrom July 2017 to January 2020, we recruited 115 housewives in Ulsan, Republic of Korea. After excluding participants with missing information, we finally included 88 Korean housewives in our study. We measured the concentrations of indoor PM using a gravimetric method 24 h before blood sampling and the concentrations of Cd, Pb, and Hg in blood, twice at a 1-year interval. We used a linear mixed effect model to estimate the associations between indoor PM and blood heavy metals. ResultsExposure to PM10 was significantly associated with blood concentrations of Cd among Korean housewives. A 10 μg/m3 increase of PM10 the previous day was associated with a 2.8% (95% confidence interval (CI) = 1.1%, 4.6%) and a 1.5% (95% CI = −0.1%, 3.1%) increase in blood concentrations of Cd and Pb in the linear mixed effect model, respectively. ConclusionThere was a significant association between indoor PM exposure and blood Cd concentrations among Korean housewives. This result suggests that the body burden of heavy metals is significantly associated with air pollution.

Distribution, bioaccessibility, and health risk assessment of heavy metals in PM2.5 and PM10 during winter heating periods in five types of cities in Northeast China

PM2.5 and PM10 samples were collected from the outdoor environment of five types of cities (provincial central cities, regional central cities, resource-based cities, agricultural cities, and forested cities) situated in Northeast China. Based on bioaccessibility and respiratory deposition fluxes, health risks of PM2.5- and PM10-bound six heavy metals [HM6: Arsenic (As), Chromium (Cr), Cadmium (Cd), Nickel (Ni), Cobalt (Co), and Lead (Pb)] were studied. Cobalt (Co) and Cr were found to be the most abundantly bioaccessible fraction among HM6 after extraction of simulated lung fluids. After inhalation exposure, among HM6, Co mainly contributed 88.39–93.19% to the non-carcinogenic risk, while Cr account for 82.92–93.72% of cancer risk. The estimated daily intake of bioaccessible HM6 in outdoor environment during the heating period was calculated to be 293.11 ± 121.03, 117.08 ± 32.46, 105.57 ± 32.49, 100.35 ± 25.58 and 83.11 ± 17.64 ng/h for provincial central cities, regional central cities, agricultural city, resource-based cities and forested cities, respectively, for local residents. During the heating period of 180 days, non-carcinogenic risks (As, Cr, Cd, Ni, Co) in outdoor environment of 0.5 residence time were below the safety threshold (HQ < 1). Cancer risks for Cr and Co were above 10−5 in the five types of cities, but in the assumable range (< 10−4). Our study highlighted the wide range of measures needed to cut airborne particles pollution to safer levels.

Assessment of Pollution and Health Risks of Heavy Metals in Particulate Matter and Road Dust Along the Road Network of Dhanbad, India.

Background.The rise in particulate matter (PM) concentrations is a serious problem for the environment. Heavy metals associated with PM10, PM2.5, and road dust adversely affect human health. Different methods have been used to assess heavy metal contamination in PM10, PM2.5, and road dust and source apportionment of these heavy metals. These assessment tools utilize pollution indices and health risk assessment models.Objectives.The present study evaluates the total mass and average concentrations of heavy metals in PM10, PM2.5, and road dust along selected road networks in Dhanbad, India, analyzes the source apportionment of heavy metals, and assesses associated human health risks.Methods.A total of 112 PM samples and 21 road dust samples were collected from six stations and one background site in Dhanbad, India from December 2015 to February 2016, and were analyzed for heavy metals (iron (Fe), lead (Pb), cadmium (Cd), nickel (Ni), copper (Cu), chromium (Cr), and zinc (Zn)) using atomic absorption spectrophotometry. Source apportionment was determined using principal component analysis. A health risk assessment of heavy metal concentrations in PM10, PM2.5, and road dust was also performed.Results.The average mass concentration was found to be 229.54±118.40 μg m−3 for PM10 and 129.73 ±61.74 μg m−3 for PM2.5. The average concentration of heavy metals was found to be higher in PM2.5 than PM10. The pollution load index value of PM10 and PM2.5 road dust was found to be in the deteriorating category. Vehicles were the major source of pollution. The non-carcinogenic effects on children and adults were found to be within acceptable limits. The heavy metals present in PM and road dust posed a health risk in the order of road dust> PM10> and PM2.5. Particulate matter posed higher health risks than road dust due to particle size.Conclusions.The mass concentration analysis indicates serious PM10 and PM2.5 contamination in the study area. Vehicle traffic was the major source of heavy metals in PM10, PM2.5, and road dust. In terms of non-carcinogenic risks posed by heavy metals in the present study, children were more affected than adults. The carcinogenic risk posed by the heavy metals was negligible.Competing Interests.The authors declare no competing financial interests

Characteristics of indoor air pollutants and estimation of their exposure dose

Rural areas of developing countries have various indoor air pollution sources along with solid fuels used for cooking. This study aims to compare five indoor air pollution sources, viz., incense stick, dhoop, mosquito coil, cigarette, and cooking fuel charcoal, with respect to their pollution potential. The monitoring of PM, CO, CO2, NO2, and particulate bound heavy metals was carried out. Dhoop (DH1) was found to be emitting the highest concentration of metal Sb among all the analyzed metals. Dhoop, incense sticks, mosquito coil, and charcoal were found to be having high pollution potential. The first-order decay rate equation indicated that the highest decay rate constant per hour was observed with dhoop (DH1) for PM10 and PM2.5 and with mosquito coil (M1) for CO. The highest half-life of PM10 and PM2.5 was observed for cigarette (CG1) and charcoal (C1) respectively indicating their slow decay in air. The average daily dose values indicated that the age group 6 to < 11 years, 11 to < 16 years, and 31 to < 51 years will be more vulnerable to PM emissions from dhoop (DH1) and incense stick (IS1). The highest hazard index was estimated for incense stick (IS1) and charcoal. Significant carcinogenic risk was observed from cigarette and charcoal. The multiple-path particle dosimetry (MPPD) model was used to estimate the deposition of PM fractions in various regions of the human body.

Pilot study on assessment of trace metals in PM10 at road sites in Bac Giang province, Vietnam

In this study, characterization of PM10 mass and its trace metals concentration at road sites in Bac Giang province located in the North of Vietnam during two different seasons has been performed. PM10 samples at 11 road sites using the high volume SIBATA HV-500R (Japan) at the flow rate of 400 L/min were collected during 10 hours (from 7:00 to 17:00) at flat low-lying plain, midland, mountain and highland areas. Data on PM10 mass and metals were used to estimate the pollution level of PM10 and trace elements bounded with PM10. The results showed that 10-hour mean PM10 concentrations at road sites in Bac Giang ranged from 103.4 µg/m3 to 577.9 µg/m3 with the average value of 292.6 µg/m3. Generally, the level of trace metals appeared to be higher in autumn than that in summer period. Additionally, concentrations of trace metals were higher at the sites with high traffic density than those with low traffic density. While the concentrations of Cd, Mn and Cr exceeded the guideline values of WHO, arsenic concentration was larger than the concentration limit of EU Directives. The degree of contamination values suggested that level of metal was high contamination at flat low-lying plain, while those values were from low to considerable contamination at the mountain and highland areas. The pollution load index values at most of sampling sites were larger than 1, which indicated the existence of dust pollution at road sides in Bac Giang province.&#x0D; Keywords:&#x0D; PM10; trace metals; degree of contamination; pollution load index, roadsides.

Pollution Characteristics and Health Risk Assessment of Heavy Metals in PM2.5 Collected in Baoding

To reveal the pollution characteristics and the health risks of the trace heavy metals in the atmospheric particles in Baoding, Hebei province, PM2.5 samples were collected using a middle volume sampler, and the mass concentrations of V, Cr, Mn, Co, Ni, Cu, Zn, As, Cd, and Pb in the samples were determined by microwave digestion-inductively coupled plasma-mass spectrometry (ICP-MS). The results showed that the PM2.5 concentration in Baoding ranged from 16.84-476.2 μg·m-3. During sampling, 65 samples were above the second-level standard of the Ambient Air Quality Standards (GB 3095-2012) by 54.2%. The most heavy metal elements showed higher levels in nighttime than during the daytime, except for except for Ni, Mn, and Co. Obvious seasonal variation was found with the trend of winter > autumn > spring > summer. The enrichment factors for Cu, Zn, Pb, and Cd were more than 1.5, indicating that those metals mainly came from anthropogenic emissions, such as traffic sources. Health risk assessment results indicated that the non-carcinogenic risk of heavy metals in PM2.5 in Baoding was small, and the carcinogenic risk resulting form As, Cr, Cd, and Co was greater for adults than for children.

4-Mercaptobenzoic acid as a MALDI matrix for highly sensitive analysis of metals.

4-Mercaptobenzoic acid (MBA) is introduced as a matrix for laser desorption/ionization time-of-flight mass spectrometry (MS) analysis of metals, exhibiting matrix-interference-free background, greatly enhanced MS signal intensity, and excellent reproducibility. The developed method was successfully extended for the rapid screening and sensitive determination of ultratrace metals in fine particulate matter (PM2.5).

Combined exposure to heavy metals in PM2.5 and pediatric asthma

Asthma is the most common chronic allergic disease in children; it affects more than 300 million people worldwide. Information on the association between exposure to ambient heavy metals and incidence of pediatric asthma is limited. We sought to evaluate the effects of heavy metals during pregnancy and infancy periods with asthma and identify a sensitive time window, clarifying the effect of ambient heavy metals on lung development. A total of 171,281 children, who were born from 2004 to 2011 in Taichung City, were followed until 2014. Concentrations of ambient heavy metals such as arsenic (As), cadmium (Cd), mercury (Hg), and lead (Pb) were obtained from the Weather Research and Forecasting/Chem model, considering the top 75 emission sources in Taiwan. The distributed lag nonlinear model was used to investigate the relationship between combined exposure to heavy metals in 2.5μm particulate matter and asthma in pregnant women and1-year-old infants. We identified 31,277 new asthma cases from the birth cohort. After adjustment for socioeconomic status, maternal age, maternal atopy, maternal anemia, and maternal kidney disease, distributed lag nonlinear model results revealed positive associations of asthma with exposure to Pb during gestational weeks 1 to 14 and 21 to 40, and 1 to 3 weeks after birth. Regarding the sensitivity analyses, coexposure to Pb and As, coexposure to Pb and Cd, and coexposure to Pb and Hg were positively associated with asthma onset as well. Our study suggested that combined exposure to Pb with As, Cd, and Hg during early and late gestational weeks was associated with the incidence of pediatric asthma.

Health risk assessment of construction workers from trace metals in PM2.5 from Kolkata, India

Construction activities have long been recognized as a pertinent source of PM2.5 though limited information exists regarding chemical characteristics of aerosols generated during building demolition/construction. A comprehensive investigation was carried out to assess the physical (SEM analysis) and chemical (ICP MS analysis) properties of PM2.5 in a building demolition and construction site and compared with background. Average concentrations of PM2.5 at both the sites exceeded the National Ambient Air Quality Standards (NAAQS). Overall trend of the total metal concentrations of PM2.5 followed the order of (Na, Ca, Al, Mg, Fe, Zn) > (Ti, Sr, Cd, Ba, Pb, V, Cr, Mn, Co, Ni, Cu) in both the sites. Sr, Ba, Mg, Zn, Ti, Cd, Al, Cr, Fe, Co, Mn, V, Ni, Ca, and Zn showed a ∼1.3-3.0 fold increase, and Pb showed the highest increase of almost >3.5 times when compared to the background concentrations. Health risk estimates based on the bio-available concentration of metals indicated that hazard quotient (HQ) values for non-carcinogenic metals were within the prescribed limit (HQ ≤ 1). However, the excess lifetime cancer risk (ELCR) for the carcinogenic metals Pb, Ni, Cd, and Cr(VI) were higher than the guideline limits of USEPA.

Large global variations in measured airborne metal concentrations driven by anthropogenic sources

Globally consistent measurements of airborne metal concentrations in fine particulate matter (PM2.5) are important for understanding potential health impacts, prioritizing air pollution mitigation strategies, and enabling global chemical transport model development. PM2.5 filter samples (N ~ 800 from 19 locations) collected from a globally distributed surface particulate matter sampling network (SPARTAN) between January 2013 and April 2019 were analyzed for particulate mass and trace metals content. Metal concentrations exhibited pronounced spatial variation, primarily driven by anthropogenic activities. PM2.5 levels of lead, arsenic, chromium, and zinc were significantly enriched at some locations by factors of 100–3000 compared to crustal concentrations. Levels of metals in PM2.5 and PM10 exceeded health guidelines at multiple sites. For example, Dhaka and Kanpur sites exceeded the US National Ambient Air 3-month Quality Standard for lead (150 ng m−3). Kanpur, Hanoi, Beijing and Dhaka sites had annual mean arsenic concentrations that approached or exceeded the World Health Organization’s risk level for arsenic (6.6 ng m−3). The high concentrations of several potentially harmful metals in densely populated cites worldwide motivates expanded measurements and analyses.