Heavy Metals In Particulate Matter Research Articles

Comprehensive source identification of heavy metals in atmospheric particulate matter in a megacity: A case study of Hangzhou

Megacities face significant pollution challenges, particularly the elevated levels of heavy metals (HMs) in particulate matter (PM). Despite the advent of interdisciplinary and advanced methods for HM source analysis, integrating and applying these approaches to identify HM sources in PM remains a hurdle. This study employs a year-long daily sampling dataset for PM1 and PM1-10 to examine the patterns of HM concentrations under hazy, clean, and rainy conditions in Hangzhou City, aiming to pinpoint the primary sources of HMs in PM. Contrary to other HMs that remained within acceptable limits, the annual average concentrations of Cd and Ni were found to be 20.6 ± 13.6 and 46.9 ± 34.8 ng/m³, respectively, surpassing the World Health Organization's limits by 4.1 and 1.9 times. Remarkably, Cd levels decreased on hazy days, whereas Ni levels were observed to rise on rainy days. Using principal component analysis (PCA), enrichment factor (EF), and backward trajectory analysis, Fe, Mn, Cu, and Zn were determined to be primarily derived from traffic emissions, and there was an interaction between remote migration and local emissions in haze weather. Isotope analysis reveals that Pb concentrations in the Hangzhou region were primarily influenced by emissions from unleaded gasoline, coal combustion, and municipal solid waste incineration, with additional impact from long-range transport; it also highlights nuanced differences between PM1 and PM1-10. Pb isotope and PCA analyses indicate that Ni primarily stemmed from waste incineration emissions. This explanation accounts for the observed higher Ni concentrations on rainy days. Backward trajectory cluster analysis revealed that southern airflows were the primary source of high Cd concentrations on clean days in Hangzhou City. This study employs a multifaceted approach and cross-validation to successfully delineate the sources of HMs in Hangzhou's PM. It offers a methodology for the precise and reliable analysis of complex HM sources in megacity PM.

Association between exposure to heavy metals in atmospheric particulate matter and sleep quality: A nationwide data linkage study

BackgroundRecent studies have demonstrated that long-term exposure to particulate matter (PM) is associated with poor sleep quality. However, no studies have linked PM constituents, particularly heavy metals, to sleep quality. ObjectiveThis study investigated the association between exposure to heavy metals in PM and sleep quality. MethodsWe obtained nationwide data from the Korean Community Health Survey conducted in 2018 among adults aged 19–80 years. Sleep quality was evaluated using Pittsburgh Sleep Quality Index (PSQI). Poor sleep quality was defined as PSQI ≥5. One-year and three-month average concentrations of heavy metals (lead, manganese, cadmium, and aluminum) in PM with diameter ≤10 μm were obtained from nationwide air quality monitoring data and linked to the survey data based on individual district-level residential addresses. Logistic regression analyses were performed after adjusting for age, gender, education level, marital status, smoking status, alcohol consumption, history of hypertension, and history of diabetes mellitus. ResultsOf 32,050 participants, 17,082 (53.3%) reported poor sleep quality. Increases in log-transformed one-year average lead (odds ratio, 1.14; 95% confidence interval, 1.08−1.20), manganese (1.31; 1.25−1.37), cadmium (1.03; 1.00−1.05), and aluminum concentrations (1.17; 1.10−1.25) were associated with poor sleep quality. Increases in log-transformed three-month average manganese (odds ratio, 1.13; 95% confidence interval, 1.09−1.17) and aluminum concentrations (1.28; 1.21−1.35) were associated with poor sleep quality. ConclusionWe showed for the first time that exposure to airborne lead, manganese, cadmium, and aluminum were associated with poor sleep quality. This study may be limited by self-reported sleep quality and district-level exposure data.

Evaluation of Toxic Heavy Metals and Health Risk in Airborne Particulate Matter at Qassim region, Saudi Arabia

Particulate matter (PM) significantly influences air quality, visibility, climate change, the earth’s radiative balance, and human health. The significance of carrying out this investigation in its entirety is due to the small amount of data that has been collected and published in Qassim region (26.2078º N, 43.4837º E). Understanding the origins of PM and its chemical species in Qassim districts is advantageous for the purpose of identifying impacts on one’s health Characterization of pollution sources also will assist in the success of mitigation strategies and solve the issue of increased PM concentrations in outdoor areas. Therefore, this study described the physical and chemical properties of PM by measuring the PM1, PM2.5, and PM10 concentrations in Qassim’s central urban and rural areas. In urban Qassim, the average PM1, PM2.5, and PM10 concentrations were 12.23, 33.16, and 155.38 µg/m3, respectively. On the other hand, the average PM1, PM2.5, and PM10 concentrations reached 8.18, 23.03, and 93.57 µg/m3 in rural Qassim, respectively. The findings revealed that fine particle concentrations have risen over allowable levels due to dust storms. A total of 18 elements and 8 chemical compounds were determined and identified. The compound concentrations of Al2O3, SiO2, CaO, TiO2, K2O, BaO, MnO, Fe2O3 and the essential elements Sr, V, Al, Cu, Ca, Fe, Cr, As, Zr, K, Br, Ba, Pb, Mn, Ni, Zn, Rb and Ti were determined using XRF and XRD. The findings revealed that fine particle concentrations have risen over allowable levels due to dust storms. The main elements in the trace elements were Ca, Fe, Al, Sr, K, and Mg, indicating significant contributions from the soil (Ca, Fe, Al, Mg), as well as from industrial and vehicle emissions (Sr, Ca, Al, Fe, K). V, Cu, Zn, Cr, Ni, Pb, Sr, As, Mn and Br fall under the anthropogenic category of trace elements, while Al, S, Na, Mg, Rb, K, Zr, Ti, Fe, Mn, Sr, Y, Cr, Ca, Ni, Zn and Cu are obtained from the earth's crust. HIGHLIGHTS The study measured levels of toxic heavy metals in airborne particulate matter (PM) in the Qassim region of Saudi Arabia The results indicated that the concentrations PM were higher than the recommended guidelines set by the World Health Organization (WHO), which poses a potential health risk to the population The study suggests that the major sources of heavy metals in the Qassim region are from dust storms and anthropogenic activities such as industrial activities and traffic emissions The study highlights the importance of regular monitoring of heavy metals in PM and the need for effective pollution control measures to protect public health GRAPHICAL ABSTRACT

Prenatal and postnatal exposure to heavy metals in PM2.5 and autism spectrum disorder

Autism spectrum disorder (ASD) is a group of neurodevelopmental disorders, and its incidence is increasing over time. Although several environmental factors have been suspected to be risk factors for ASD, studies on the effects of airborne heavy metals on newly developed ASD are still limited. We conducted a large birth cohort study of 168,062 live term births in Taichung during 2004–2011 to assess the association of heavy metals in particulate matter with an aerodynamic diameter less than 2.5 μm (PM2.5) with ASD, and identify sensitive time windows during prenatal and postnatal periods. Heavy metals, including arsenic (As), cadmium (Cd), mercury (Hg), and lead (Pb) in PM2.5, were estimated using the Weather Research and Forecasting/Chem (WRF/Chem), inserted from the top 75 emission sources for the module. The association between childhood ASD and 4 metals were analyzed from pregnancy to 9 months after birth. The Cox proportional hazard model with a distributed lag nonlinear model (DLNM) was used to estimate the association between heavy metals in PM2.5 and ASD. We identified 666 incident ASD cases in 168,062 participants. A positive association between Hg and ASD was found at 9 months after birth (Hazard Ratio: 1.63; 95% CI: 1.13–2.36). According to the DLNM, there was an increased risk of exposure to Hg during 10–25 weeks after birth, and decreased risk of exposure to Hg during gestational weeks 4–6. Exposure to As and Hg on the risk of ASD were significantly stronger in low birth weight infants (<2500 g) than in those of birth weight ≥2500 g during postnatal period. Postnatal exposure to Hg in PM2.5 may associate with increased ASD incidence. Infants with low birth weight and exposure to As and Hg in PM2.5 are more likely to develop ASD.

In Vitro Bioaccessibility and Health Risk of Heavy Metals from PM2.5/PM10 in Arid Areas—Hotan City, China

The impact of heavy metals in particulates plays an assignable role in human health—especially in the northwest region of China, which is affected by severe dust storms—and the bioaccessibility and health risks of heavy metals in particulate matter have not yet been quantified and evaluated. This study used Gamble’s solution and PBET (physiologically based extraction test) experiments to simulate the human respiratory and digestive systems, and analyzed the concentrations and bioaccessibility of Pb, Mn, Ni, Cd and As in PM2.5 and PM10 samples in the urban area of Hotan City during summer (July) and winter (January). The result shows that Mn and Pb are the most abundant elements in five metals. The bioaccessibility of Mn in gastric fluid was the highest in both summer (PM2.5: 64.1%, PM10: 52.0%) and winter (PM2.5: 88.0%, PM10: 85.1%). Meanwhile, in the respiratory system, the highest bioaccessibility of PM2.5 and PM10 in summer was Ni (53.3%), and Pb (47.9%), respectively. Although the concentration of Cd is low in winter, its bioaccessibility in lung fluid was the highest (PM2.5: 74.7%, PM10: 62.3%). The USEPA standard model and Monte Carlo simulation results show that the heavy metals in PM2.5 and PM10 would give rise to non-carcinogenic risk for both adults and children through the respiratory system in summer but had little risk in winter. However, the metal may have non-carcinogenic risk to children through intake. In addition, there is a cancer risk to adults through the respiratory system in winter (PM2.5: CR = 1.80 × 10−6, PM10: CR = 2.82 × 10−6), while there is a carcinogenic risk through the digestive system regardless of season and age.

Risk Assessment of the Impact of Heavy Metals in Urban Traffic Dust on Human Health

Excessive exposure to heavy metals induces potential adverse health impacts in humans. More specifically, heavy metals in particulate matter (PM) have a significant impact since PM can penetrate human organs and systems, causing several morbidities. In this work, dust samples were collected from 20 different types of roads in a busy zone in Doha during the winter of 2016–2017, where a higher human exposure rate occurs due to extensive outdoor activities during this time of the year. The elemental composition in terms of the mass concentration of 30 elements was determined in each sample via an energy-dispersive X-ray fluorescence (XRF) spectrometer. Then, the toxicity of six heavy metals in these airborne traffic dust samples was investigated. The heavy metals reported to have a hazardous impact on human health are As, Pb, Hg, Cd, Cr, Co, Ni, Cu, and Zn. The extent of carcinogenic and non-carcinogenic risk impact was assessed using pollution indices and then determining the health risks associated with exposure to heavy metals through inhalation, ingestion, and dermal contact. The non-carcinogenic hazard index analysis results indicate no toxicity for all metals. However, the carcinogenic risk factor results show that only chromium might induce a slight risk for children and adults. In light of this, further research is recommended to investigate more areas in urban Doha where more samples can be collected and analyzed.

Estimation of Heavy Metals Content at Traffic Inter-Change Ita-Marun Epe Lagos State Nigeria

This study assesses the vehicular and traffic emission at Ita-marun Epe Lagos State. Road traffic area contains contaminants which affects human, animals and plants. Hence, the need to investigate the concentrations of these contaminants within the selected area. Three deposition gauges of 0.15 by 0.20 mm were planted at selected sampling site for 30 days between December 2021 and January 2022. The Lagos State University Epe campus was used as the control experiment for this research work. Deposition flux for each site was determined. The contaminants levels of the heavy metals in particulate matter were evaluated using the Enrichment Factor (EF) analysis. Deposition fluxes determined range from 31.8269-39.7836 g/m2/month at the sampling site while it ranges 42.3934-51.0567 g/m2/month at control site. Elemental analyses of all the samples collected were determined using the Energy Dispersive X-ray Fluorescence (EDXRF). EF reveals that 7 elements Ag, Cd, Cr, In, Mn, Sn, and Zn are highly enriched at sampling site while 6 elements S, Cl, Zn, Ge, As and W at the control site respectively. Results shows that fluxes at the control site were higher than that of the sampling site. EF also reveals that seven elements at the sampling site and six elements at the control site were anthropogenically derived. Due to the findings of this research, a clean-up of this area is highly recommended.

On the nature of heavy metals in particulate matter (PM10, PM2.5) and their health impact assessment for a desert city in Iran, Birjand

&#x0D; &#x0D; &#x0D; &#x0D; Introduction: Air pollution is the leading environmental risk factor for health. This study aimed to assess heavy metals in Particulate Matter (PM10 , PM2.5) and their health impact assessment for a desert city in Iran, Birjand.&#x0D; Materials and methods: In this study, the concentrations of PM10 and PM2.5 were measured from September 2019 to March 2020. Measurements were performed once every six days for 24 h using high-volume samplers. Moreover, health-related effects attributed to the suspended particles were estimated using the AirQ2.2.3.&#x0D; Results: Mean and standard deviation of PM10 and PM2.5 concentrations were 97.5±38.7 μg/m3 and 36.3±19.1 μg/m3, respectively. The mean metal concentrations in PM2.5 were in the Co&gt;Cd&gt;Ce&gt;V order, while the metal concentrations in PM10 were in the Cd&gt;As&gt;Ce&gt;V order. The lowest and highest number of deaths attributed to PM2.5 per 100,000 persons were related to ischemic heart disease (1.73) and chronic respiratory disease (18.35). The highest number of deaths attributed to PM10 per 100,000 persons was related to chronic bronchitis in adults (35.74).&#x0D; Conclusion: This study revealed that particle-based air pollution negatively affects health as caused by heavy metals, whereas further research is required to determine the effects of bacterial and fungal bioaerosols on human health. Monitoring the elemental composition of atmospheric particles can contribute to better air quality management.&#x0D; &#x0D; &#x0D; &#x0D;

Characteristics and health risk assessment of heavy metal pollution in atmospheric particulate matter in different regions of the Yellow River Delta in China.

To understand the characteristics, temporal and spatial variation, and health risks of atmospheric heavy metal pollution in different areas of the YRD (Yellow River Delta), atmospheric particles samples were collected in the YRD in China during 2016-2017. A total of 10 monitoring points were chosen in different areas (industrial parks, main urban areas, and rural areas) in the YRD, heavy metals were monitored using atomic fluorescence spectrometry and graphite furnace atomic absorption spectrometry. The results showed that TSP (total suspended particulate), PM10 (particulate matter with an aerodynamic diameter less than 10μm), and PM2.5 (particulate matter with an aerodynamic diameter less than 2.5μm) contents were higher in the Kenli EDZ (economic development zone) and Kenli urban areas than those in other points. The concentration range of heavy metals in atmospheric samples at 10 points was different, with a difference of five orders of magnitude, of which the content of copper (Cu) was the highest, with the highest concentration of 4.375μg/m3, and the content of particulate mercury (Hg) was the lowest, with the minimum concentration of 0.00001μg/m3. Among the nine heavy metals, the contents of cadmium (Cd), lead (Pb), and Hg were higher in winter than in summer, and chromium (Cr), nickel (Ni), Cu, and manganese (Mn) were higher in summer than in winter. In addition to Hg, the contents of the other eight heavy metals in particulate matter showed a trend that urban areas and EDZs had higher concentrations than cities and towns and nature reserves, which can be attributed to industrial activities and coal-fired fuel emissions. Health risk assessment was carried out for adults and children, respectively, and the results showed that carcinogens have no obvious carcinogenic risk, but As and Cr have major potential carcinogenic risk. Among the noncarcinogenic substances, Mn has the greatest noncarcinogenic risk, and urban areas and economic development zones have the greatest risk. This study investigated the characteristics and health risk assessment of atmospheric heavy metal pollution in different areas in the YRD to supplement the research contents of atmospheric particulate heavy metals in the YRD in domestics and overseas. It is also critical to study the pollution and migration of heavy metals in China.

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.

Elemental Characteristics of Respirable Particulate Matter in the Urban Atmosphere of Dehradun, Uttrakhand, India

To evaluate the ambient air quality of the Dehradun city, respirable particulate matter was collected using respirable dust sampler (RDS) and analysed for the heavy metal content using atomic absorption spectroscopy (AAS). The morphology of particulates were determined using scanning electron microscope (SEM) and the elemental composition was determined through SEM- energy dispersive spectroscopy (EDS). Particulate matter mass concentration ranged from 65.00 µg m-3 to 337.33 µg m-3. Quantified heavy metals in particulate matter were Copper (Cu), Zinc (Zn), Cobalt (Co), Manganese (Mn), Iron (Fe), Nickel (Ni), Chromium (Cr), Lead (Pb) and Cadmium (Cd). The order of concentration of heavy metals were found to be in the trend of Fe&gt;Zn&gt;Cu&gt;Pb&gt;Cr&gt;Ni&gt;Mn&gt;Co&gt;Cd. Maximum concentration of PM10 was found at commercial site during summer, winter and monsoon season. Enrichment factor analysis showed substantial contribution of anthropogenic activities on PM10. Source apportionment (varimax rotated factor analysis method) showed dominance of incineration and uncontrolled burning of waste and refuses, resuspended dust with vehicular emission and crustal sources as the dominant sources in Dehradun. Plantation drive strategy have major role in ambient particulate matter mitigation measures and carbon sequestration from climate change and global problem worldwide. This study will be help to mitigate or decrease the load of air pollution by the using of various trees for sustainable human development on the marvellous earth planet.

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

Indoor air quality in rural Southwestern Uganda: particulate matter, heavy metals and carbon monoxide in kitchens using charcoal fuel in Mbarara Municipality

The use of biomass energy over open fires in sub-Saharan Africa is rampant yet it is associated with air pollution. Information on the contribution of common biomass like charcoal to indoor air pollution in Uganda is scarce; therefore, kitchen-indoor air in charcoal fueled kitchens was characterized for fine particulate matter (PM2.5), heavy metals and carbon monoxide content in Mbarara Municipality Western Uganda. PM2.5 was measured using University of California Berkeley Particle and Temperature Sensor (UCB-PATS), heavy metals were determined using Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES) and carbon monoxide was measured using a portable, battery-operated, data-logging Drager Pac 7000. In the kitchens assessed, the mean 24-h concentration for PM2.5 was 0.449 mg/m3 in the wet season and 0.526 mg/m3 in the dry season; CO was 41.52 ppm, and all concentrations were higher than the World Health Organization 24-h Air Quality Guideline for PM2.5 of 0.024 mg/m3 and CO of 6.340 ppm. Heavy metals in particulate matter were in concentration ranges of 1.012–9.820 μg/m3 Fe, 0.012–0.092 μg/m3 Cr, 0.060–10.750 μg/m3 Zn, 0.048–0.300 μg/m3 Cu, 0.004–0.052 μg/m3 Pb and ND—0.004 μg/m3 Cd. All mean metal concentrations were lower than recommended exposure levels by EPA although chronic exposure is a risk to health. Kitchen ventilation and size were found to significantly influence indoor pollutant levels; charcoal fuel significantly contributed to indoor air pollution and is therefore a risk factor to human health.

Determination of oxoanions and water-soluble species of arsenic, selenium, antimony, vanadium, and chromium eluted in water from airborne fine particles (PM2.5): effect of acid and transition metal content of particles on heavy metal elution.

Heavy metals in particulate matter (PM) are of great concern, and their effects on the environment and human health depend on their solubilities and species present. In this study, the solubility of As, Se, Sb, V and Cr and their species eluted in water was investigated. As, Se, Sb, and V were present mostly in fine particles, and they were predominantly water-soluble in fine particles (<2.5 μm, PM2.5) but insoluble in coarse particles (>2.5 μm). Solubility of Cr was poor even in fine particles. It was found that for fine particles, solubilities of the heavy metals were related to the nitrate and sulfate contents. This suggests that the higher the acidity of the particles, the higher the solubility of the heavy metals. Oxoanions of the five kinds of heavy metals in water extracts of fine particles were determined by inductively coupled plasma mass spectrometry preceded by ion chromatography. The results suggested the presence of atmospheric oxidation during the aerosol transportation. Also, the As(iii)/As(v) (arsenite/arsenate) ratios for the fine particle extracts were related to the transition metal concentrations, which indicated that Fe, Cu, etc. in fine particles affected the As redox equilibrium. It was suggested that the heavy metals exist as complexes with iron hydroxide and dissolved organic matter in addition to the free oxoanions. These investigations were performed for PM samples collected in winter and summer in Kumamoto, west Japan, where the site is strongly exposed to westerly winds from continental East Asia. The obtained results improve our understanding of the behavior of the heavy metals in airborne PM after depositing on a wet environment and biota.

Protective Effect of Breastfeeding on the Adverse Health Effects Induced by Air Pollution: Current Evidence and Possible Mechanisms.

Air pollution is a major social, economic, and health problem around the world. Children are particularly susceptible to the negative effects of air pollution due to their immaturity and excessive growth and development. The aims of this narrative review were to: (1) summarize evidence about the protective effects of breastfeeding on the adverse health effects of air pollution exposure, (2) define and describe the potential mechanisms underlying the protective effects of breastfeeding, and (3) examine the potential effects of air pollution on breastmilk composition and lactation. A literature search was conducted using electronic databases. Existing evidence suggests that breastfeeding has a protective effect on adverse outcomes of indoor and outdoor air pollution exposure in respiratory (infections, lung function, asthma symptoms) and immune (allergic, nervous and cardiovascular) systems, as well as under-five mortality in both developing and developed countries. However, some studies reported no protective effect of breastfeeding or even negative effects of breastfeeding for under-five mortality. Several possible mechanisms of the breastfeeding protective effect were proposed, including the beneficial influence of breastfeeding on immune, respiratory, and nervous systems, which are related to the immunomodulatory, anti-inflammatory, anti-oxidant, and neuroprotective properties of breastmilk. Breastmilk components responsible for its protective effect against air pollutants exposure may be long chain polyunsaturated fatty acids (LC PUFA), antioxidant vitamins, carotenoids, flavonoids, immunoglobins, and cytokines, some of which have concentrations that are diet-dependent. However, maternal exposure to air pollution is related to increased breastmilk concentrations of pollutants (e.g., Polycyclic aromatic hydrocarbons (PAHs) or heavy metals in particulate matter (PM)). Nonetheless, environmental studies have confirmed that breastmilk’s protective effects outweigh its potential health risk to the infant. Mothers should be encouraged and supported to breastfeed their infants due to its unique health benefits, as well as its limited ecological footprint, which is associated with decreased waste production and the emission of pollutants.

Pollution Characteristics of Heavy Metals in PM2.5 Near Highway

In this study, we evaluate the pollution characteristics of heavy metals in particulate matter with diameters less than 2.5 μm (PM2.5) near highways. Three rounds of cluster sampling of PM2.5 were conducted on three highways, Changzhang, Changtong, and Wenhou, in peri-urban areas near Nanchang from March to August 2018. The sampling sites included service areas, toll stations, tunnels, and areas near the highway. The concentrations of six heavy metals including Cu, Zn, Pb, Cd, Cr, and Ni in PM2.5 were analyzed using inductively coupled plasma mass spectrometry (ICP-MS). The pollution and distribution of heavy metals in PM2.5 near the highway were analyzed, and that pollution characteristics and the level of possible ecological jeopardy were assessed by using the Geoaccumulation Index and Potential Risk Index methods. No significant difference was observed in PM2.5 or in heavy metals in PM2.5 along highways with different traffic flow, but they differed significantly in among highway settings in the following order:super-long tunnels > long tunnels and area near the highway > service areas and toll stations. The heavy metal concentration in highways decreased in the following order:Zn (3.8 μg·m-3) > Pb (10.2×10-2 μg·m-3) > Cr (6.8×10-2 μg·m-3) > Cu (3.5×10-2 μg·m-3) > Ni (1.5×10-2 μg·m-3) > Cd (0.1×10-2 μg·m-3). In accordance with the influence of temperature and precipitation, PM2.5 and heavy metals in PM2.5 showed significant variations among the monitoring months. The PM2.5 concentration had a significant negative correlation with atmospheric temperature. We observed that PM2.5 concentration was significantly lower from May to August than from March to April. The Zn concentration in PM2.5 was more significant from May to August than from March to April. Pearson analysis showed a significant positive correlation between Zn in PM2.5 with atmospheric temperature because elevated temperatures could aggravate wear and tear and metallic corrosion, which then prompts the emission of Zn. According to the Geoaccumulation Index and Potential Ecological Jeopardy Index, the level of pollution associated with heavy metals of PM2.5 manifested in the following order:Zn and Cd > Pb > Cu > Ni and Cr. The pollution and degree of jeopardy associated with Zn and Cd were the most severe in the assessment criteria; therefore, the pollution by these elements and the sources of traffic should be noted in air pollution control plans. Super long tunnels, long tunnels, and areas near highways showed greater levels of pollution and higher potential ecological jeopardy than service areas and toll stations. The degree of pollution in densely populated service areas and toll stations was consistent across partially urban areas.

Incorporating bioaccessibility into health risk assessment of heavy metals in particulate matter originated from different sources of atmospheric pollution

Rapid industrialization and urbanization have resulted in widespread pollution of airborne particulate matter (PM) containing various heavy metals with adverse human-health effects. Health risk assessment of PM calls for accurate evaluation of the bioaccessibility, instead of the total content, of heavy metals in PM. Here, we demonstrated that the leachable fraction of particle-bound As, Pb, Cr, Mn, Cd, Cu, Ni and Zn in lung fluid within the typical retention duration of particles in human lungs varied drastically among particles originated from different air pollution sources, including coal combustion, biomass combustion, fugitive dust, road dust, construction dust, cement and soil. Moreover, bioaccessibility of heavy metals, particularly in biomass combustion, cement and soil particles, was strongly dependent on pollution sources, and the particulate Cu, Ni, Pb and Cd appeared to be the primary indicators of the source dependence of heavy metal bioaccessibility. Using total rather than bioaccessible concentrations of particle-bound heavy metals not only led to overestimation of the health risk of source particles, but more importantly, inaccurate identification of the high-risk pollution sources and the priority metal pollutants in the source particles. When considering bioaccessibility of particle-bound heavy metals examined in this study, coal combustion products exhibited the highest carcinogenic and noncarcinogenic risks among all source particles, whereas cement particles would be the source with highest risk based on total metal content. As and Mn appeared to be the main drivers for the noncarcinogenic risks of source particles, while As, Ni and Cr were the major contributors to the carcinogenic risks of source particles, significantly different from those based on total contents. This research underlines the importance of incorporating bioaccessibility into health risk indexes of frequently occurring particle-bound heavy metals from specific air pollution sources, which will facilitate risk-based assessment of source contribution and hence effective source regulation of airborne PM.

Size distribution and source of heavy metals in particulate matter on the lead and zinc smelting affected area

In order to understand the size distribution and the main kind of heavy metals in particulate matter on the lead and zinc smelting affected area, particulate matter (PM) and the source samples were collected in Zhuzhou, Hunan Province from December 2011 to January 2012 and the results were discussed and interpreted. Atmospheric particles were collected with different sizes by a cascade impactor. The concentrations of heavy metals in atmospheric particles of different sizes, collected from the air and from factories, were measured using an inductively coupled plasma mass spectrometry (ICP-MS). The results indicated that the average concentration of PM, chromium (Cr), arsenic (As), cadmium (Cd) and lead (Pb) in PM was 177.3 ± 33.2 μg/m3, 37.3 ± 8.8 ng/m3, 17.3 ± 8.1 ng/m3, 4.8 ± 3.1 ng/m3 and 141.6 ± 49.1 ng/m3, respectively. The size distribution of PM displayed a bimodal distribution; the maximum PM size distribution was at 1.1–2.1 μm, followed by 9–10 μm. The size distribution of As, Cd and Pb in PM was similar to the distribution of the PM mass, with peaks observed at the range of 1.1–2.1 μm and 9–10 μm ranges while for Cr, only a single-mode at 4.7–5.8 μm was observed. PM (64.7%), As (72.5%), Cd (72.2%) and Pb (75.8%) were associated with the fine mode below 2.1 μm, respectively, while Cr (46.6%) was associated with the coarse mode. The size distribution characteristics, enrichment factor, correlation coefficient values, source information and the analysis of source samples showed that As, Cd and Pb in PM were the typical heavy metal in lead and zinc smelting affected areas, which originated mainly from lead and zinc smelting sources.

Role of heavy metals in structuring the microbial community associated with particulate matter in a tropical estuary

Particulate matter (PM), which are chemically and biochemically complicated particles, accommodate a plethora of microorganisms. In the present study, we report the influence of heavy metal pollution on the abundance and community structure of archaea and bacteria associated with PM samples collected from polluted and non-polluted regions of Cochin Estuary (CE), Southwest coast of India. We observed an accumulation of heavy metals in PM collected from CE, and their concentrations were in the order Fe > Zn > Mn > Cr > Pb > Cu > Cd > Co > Ni. Zinc was a major pollutant in the water (4.36–130.50 μgL−1) and in the particulate matter (765.5–8451.28 μgg−1). Heavy metals, Cd, Co, and Pb were recorded in the particulate matter, although they were below detectable limits in the water column. Statistical analysis showed a positive influence of particulate organic carbon, nitrogen, PM-Pb, PM-Zn and PM-Fe on the abundance of PM-archaea and PM-bacteria. The abundance of archaea and bacteria were ten times less in PM compared with planktonic ones. The abundance of PM-archaea ranged between 4.27 and 9.50 × 107and 2.73 to 3.85 × 107 cellsL−1 respectively for the wet and dry season, while that of PM-bacteria was between 1.14 and 6.72 × 108 cellsL−1 for both seasons. Community structure of PM-bacteria varied between polluted and non-polluted stations, while their abundance does not show a drastic difference. This could be attributed to the selective enrichment of bacteria by heavy metals in PM. Such enrichment may only promote the growth of metal resistant archaea and bacteria, which may not participate in the processing of PM. In such cases, the PM may remain without remineralization in the system arresting the food web dynamics and biogeochemical cycles.

Heavy metals in industrially emitted particulate matter in Ile-Ife, Nigeria

Iron and steel smelting facilities generate large quantities of airborne particulate matter (PM) through their various activities and production processes. The resulting PM that contains a variety of heavy metals has potentially detrimental impacts on human health and the environment. This study was conducted to assess the potential health effects of the pollution from the heavy metals in the airborne PM sampled in the vicinity of secondary smelting operations in Ile-Ife, Nigeria. X-ray fluorescence (XRF) was used to determine the elemental concentration of Pb, Cr, Cd, Zn, Mn, As, Fe, Cu, and Ni in the size-segregated PM samples. Pollution Indices (PI) consisting of Contamination Factor (CF), Degree of Contamination (DC) and Pollution Index Load (PLI) and Target Hazard Quotient (THQ) were employed to assess the pollution risk associated with the heavy metals in the PM. CF, DC and PLI values were 3< CF <6, >32 and >1, respectively for the three sites, indicating deterioration of the ambient air quality in the vicinity of the smelter. The heavy metals in the airborne PM pose a severe health risk to people living in vicinity of the facility and to its workers. The diminished air quality with the associated health risks directly depends on the industrial emissions from steel production and control measures are recommended to mitigate the likely risks.