Promethium Research Articles

Characteristic of PM2.5 concentration and source apportionment during winter in Seosan, Korea

Seosan is a concentrated industrial complex in the midwestern region of Korea. A study was conducted from December 2020 to January 2021, measuring PM2.5 and chemical components in Seosan using online instruments every hour. The concentration of PM2.5 during the winter season was 31.4±17.8 μg/m3, exceeding the national ambient air quality standard of Korea. The mass fraction of organic matter, elemental carbon, three major ions, five minor ions, crustal elements, and trace elements in PM2.5 accounted for 24.5%, 4.36%, 32.0%, 2.82%, 4.11%, and 5.17% of the total PM2.5 mass concentration, respectively. Source identification was conducted using positive matrix factorization modeling, revealing eight sources of PM2.5: Secondary inorganic aerosol (SIA), vehicle exhaust, industry, coal combustion, biomass burning/incinerator, oil combustion, soil, and aged sea salt. Source contributions varied during high pollution episodes (HPE), with SIA dominating in HPE1 and soil and aged sea salt in HPE2. The potential source contribution function and conditional probability function were utilized to estimate the potential local and regional emission areas for the identified sources. In Seosan, vehicle exhaust and biomass burning/incinerator were primarily influenced by local sources. SIA, industry, and oil combustion sources were significantly affected by short-range transport from eastern China. Soil and aged sea salt, which exhibited high contributions during HPE2, were associated with long-range transport from Inner Mongolia. Coal combustion was attributed to both local sources, particularly large industrial complexes near Seosan, and long-range transport from Northeast China and Inner Mongolia.Graphical

Iron Trace Elements Concentration in PM10 and Alzheimer's Disease in Lima, Peru: Ecological Study.

Alzheimer's disease (AD) has been linked to air pollution, especially particulate matter (PM). PM comprises various elements, including iron-rich particles that may reach the brain through inhalation. Lima, Peru is one of the most polluted cities in Latin America, with a high rate of AD. The study aims to evaluate the association between iron (Fe) trace elements in PM10 and AD cases in Lima, Peru. This retrospective ecological study used monthly Fe concentration data from the Peruvian Ministry of Health. AD cases (ICD-10-G30) and dementia in AD cases (DAD, ICD-10-F00) were obtained from the Peruvian CDC. Fe trace element data were available for six districts in Lima for the years 2017-2019 and 2022. Cases were standardized based on ≥60-year-old populations of each district. Hierarchical mixed-effects models of Gaussian and negative binomial families were constructed to evaluate both outcomes jointly (AD + DAD) and separately (AD, and DAD). A sensitivity analysis was conducted by excluding data from Lima's downtown district. In the complete model, log-Fe concentration was associated with a higher rate of AD + DAD and DAD, and with a higher IRR for the three outcomes. After controlling for other metals, a higher DAD rate was observed (β-coeff = 6.76, 95%CI 0.07; 13.46, p = 0.048), and a higher IRR for AD + DAD (1.55, 95%CI 1.09; 2.20, p = 0.014) and DAD (1.83, 95%CI 1.21; 2.78, p = 0.004). The association was not significant in the sensitivity analysis. In conclusion, exposure to Fe through PM10 inhalation may be associated with the presence of AD in Lima.

Trace elements in PM2.5 from 2016 to 2021 in Shenzhen, China: Concentrations, temporal and spatial distribution, and related human inhalation exposure risk

The prevalence of trace elements from industrial and traffic activities poses potential health risks through inhalation exposure. Prior studies have focused on trace elements in water, food, and dust, and less attention has been paid to their occurrence in fine particulate matter (PM2.5). In this study, 1424 air samples were collected from three districts (Nanshan, Longgang, and Yantian) in Shenzhen from 2016 to 2021, and we analyzed the concentrations, temporal trends, and spatial distributions of PM2.5 and associated trace elements. Both PM2.5 and trace elements exhibited decreasing trends and similar seasonal variations, with high levels in cold seasons and low levels in warm seasons. In terms of spatial distributions, the concentrations of PM2.5 and trace elements in Nanshan and Longgang were significantly higher than those in Yantian, likely due to the industrial structure and traffic activities. It is worth noting that PM2.5 was identified as a potential mediator of the effect of meteorological parameters on trace element levels. Besides, the values of estimated daily intake (EDI) and uptake (EDU) suggested that infants and young children experienced an elevated risk of exposure to trace elements. While the annual average excess hazard indexes (R) were below the safety threshold (10−6), carcinogenic trace elements like arsenic (As) and chromium (Cr) posed a greater potential threat to human health compared to non-carcinogenic trace elements.

Exploring the characteristics and source-attributed health risks associated with polycyclic aromatic hydrocarbons and metal elements in atmospheric PM2.5 during warm and cold periods in the northern metropolitan area of Taiwan

Polycyclic aromatic hydrocarbons (PAHs) and metal elements are commonly considered hazardous air pollutants due to their toxic, mutagenic, and carcinogenic properties. However, few studies have simultaneously examined their potential sources and health effects. This study aimed to quantify the PAHs and metal elements in atmospheric PM2.5, investigating their characteristics and potential sources to assess associated health risks in the northern metropolitan area of Taiwan. The measurements indicated that the mean concentrations of total PAHs and metal elements in PM2.5 were 0.97 ± 0.52 ng m−3 and 590 ± 200 ng m−3, respectively. Utilizing the positive matrix factorization profiles, the PAH pollution was classified into two sources: industrial emissions, traffic emissions, and coal combustion (69%) were the predominant sources of PAHs, with petroleum volatilization and biomass burning (31%) making a lesser contribution. Similarly, we traced metal elements to three potential sources: natural sources (48%), a combined source of industrial emissions, coal combustion, and traffic exhaust (32%), and a blend of non-exhaust emissions from traffic and waste incineration sources (20%). Results from the potential source contribution function model suggested that the emissions of PAHs and metals could be influenced by the eastern regions of China, although local sources, including waste incinerators, traffic, shipping, and harbor activities, were identified as the primary contributors. Source-attributed excess cancer risk revealed that industry, traffic, and coal combustion had the highest cancer risk posed by PAHs in the cold period (1.0 × 10−5), while the greatest cancer risk among metal elements was linked to non-exhaust emissions from traffic and waste incineration emissions (2.0 × 10−5). This research underscores the importance of considering source contributions to health risk and emission reduction when addressing PM2.5 pollution. These findings have direct implications for policymakers, providing them with valuable insights to develop strategies that protect public health from the detrimental effects of PAH and metal element exposure.

Toxic elements, sources and health risk assessment of PM2.5 in an industrial area of Surabaya, Indonesia

ABSTRACT A comprehensive study on air quality in the industrial area of Indonesia, which significantly impacts respiratory health and poses breathing hazards, is still lacking. This study aims to uncover the contents of toxic elements, identify potential sources of fine particles, and evaluate their contributions to health risks in Surabaya’s industrial area. The study focuses on identifying chemical composition, sources, and assessing health risks for both children and adults. The PM2.5 concentration from 2021 to 2022 ranged from 3.29 to 27.05 µg m−3, with an average value of 13.63 ± 4.54 µg m−3, exceeding the WHO’s annual standard of 5 µg m−3. Black carbon (BC) accounted for 27% of PM2.5 composition. A seasonal variation was found; the highest PM2.5 and BC were observed during the dry season, with the highest peak in June. The highest concentration of elements in PM2.5 was observed for S, followed by Si, K, Zn, Fe, and Pb, with maximum values of 3.53, 1.16, 1.01, 1.86, 0.29, and 0.37 µg m−3, respectively. Source apportionment using positive matrix factorisation (PMF) revealed eight sources: galvanising industry, ammonium chloride, secondary sulphate, biomass burning emission, soil, steel industry, vehicle emissions, and lead smelting, with metal industries accounting for 37.3%. Investigation into their potential source locations was conducted using the conditional bivariate probability function (CBPF) method. Human health assessment for adults and children indicates carcinogenic risks with a total risk of 9.50 × 10−5 and 2.38 × 10−5, respectively. The results emphasise the significance of managing sources linked to industry and transportation-related sources, crucial in decreasing high PM2.5 levels and several elevated elements and mitigating the health impact in Surabaya’s industrial area, Indonesia.

Bioavailability and ecological risk assessment of metal pollutants in ambient PM2.5 in Beijing

Metal pollutants in fine particulate matter (PM2.5) are physiologically toxic, threatening ecosystems through atmospheric deposition. Biotoxicity and bioavailability are mainly determined by the active speciation of metal pollutants in PM2.5. As a megacity in China, Beijing has suffered severe particulate pollution over the past two decades, and the health effects of metal pollutants in PM2.5 have received significant attention. However, there is a limited understanding of the active forms of metals in PM2.5 and their ecological risks to plants, soil or water in Beijing. It is essential that the ecological risks of metal pollutants in PM2.5 are accurately evaluated based on their bioavailability, identifying the key pollutants and revealing historic trends to future risks control. A two-year project measured the chemical speciation of pollution elements (As, Cd, Cu, Cr, Ni, Mn, Pb, Sb, Sr, Ti, and Zn) in PM2.5 in Beijing, in particular their bioavailability, assessing ecological risks and identifying key pollutants. The mass concentrations of total and active species of pollution elements were 199.12 ng/m3 and 114.97 ng/m3, respectively. Active fractions accounted for 57.7 % of the total. Cd had the highest active proportion. Based on the risk assessment code (RAC), most pollution elements except Ti had moderate or high ecological risk, with RAC exceeding 30 %. Cd, with an RAC of 70 %, presented the strongest ecological risk. Comparing our data with previous research shows that concentrations of pollution elements in PM2.5 in Beijing have decreased over the past decade. However, although the total concentrations of Cd in PM2.5 have decreased by >50 % over the past decade, based on machine model simulation, its ecological risk has reduced by only 10 %. Our research shows that the ecological risks of pollution elements remain high despite their decreasing concentrations. Controlling the active species of metal pollutants in PM2.5 in Beijing in the future is vital.

Characterization of Metal Elements in Atmospheric Fine Particulate Matter and Their Sources in Winter in the Southern Sichuan Urban Agglomeration

To investigate the concentration characteristics and sources of metal elements in PM2.5 during winter heavy pollution in the southern Sichuan urban agglomeration (Zigong, Luzhou, Neijiang, and Yibin), the metal elements in PM2.5 were measured using membrane sampling methods from December 30, 2018 to January 14, 2019, and the enrichment factor method (EF) and positive matrix factorization(PMF) were applied to investigate the sources of metal elements. The metal element observation data of Zigong in the same period of 2015 were also used to investigate the changes in metal element pollution and enrichment in Zigong in the middle and end of the implementation of China's Air Pollution Prevention and Control Action Plan. The main findings were as follows:① The concentrations and percentages of metal elements in particulate matter in different cities did not differ significantly. The elements with higher concentrations in the four cities showed similarities, with Al, Sb, and Fe at the top. From the comparison of different observation periods in Zigong, the concentrations of all elements except Tl changed. ② The results of the enrichment factor calculation showed that the enrichment of the elements Cr (Zigong and Yibin), Ni, Cu, As, Se, Ag, Cd, Sb, Tl, and Pb in the urban agglomeration was high. The comparison of the enrichment levels of elements in Zigong for different observation periods showed that the enrichment levels of all elements, except Cu, tended to decrease in the winter observation period of 2018. ③ The results of PMF source analysis showed that the metal elements in each city mainly originated from dust sources, coal-fired sources, industrial sources, and traffic sources, whereas there was a mixed contribution among the sources. The contribution of the main sources differed among cities, in which Zigong was dominated by traffic dust sources and mixed sources, Luzhou was dominated by industrial sources, Neijiang had a similar contribution from different sources, and Yibin was dominated by traffic sources.

Pollution Characteristics, Source, and Health Risk Assessment of Metal Elements in PM2.5 Between Winter and Spring in Zhengzhou

A total of 18 metal elements in ambient PM2.5 in Zhengzhou were continuously determined using an online heavy metal observation instrument in January and April, 2021, and the changes in element concentrations were analyzed. Metal elements were traced via enrichment factors, positive matrix factorization (PMF), and a characteristic radar chart. The US EPA health risk assessment model was used to assess the health risks of heavy metals, and the backward trajectory method and the concentration-weighted trajectory (CWT) method were used to evaluate the potential source regions of health risks. The results showed that the element concentrations were higher in spring, and the sum of Fe, Ca, Si, and Al concentrations accounted for 89.8% and 87.5% of the total element concentrations in winter and spring, respectively. Cd was enriched significantly, which was related to human activities. The concentrations of Pb, Se, Zn, Ni, Sb, and K in winter and Cr, Ni, Fe, Mn, V, Ba, Ca, K, Si, and Al in spring increased with the increasing pollution level. The results of PMF and the characteristic radar chart showed that the main sources of metal elements in winter and spring were industry, crust, motor vehicles, and mixed combustion, with industry and mixed combustion pollution occurring more often in winter and crust pollution occurring more often in spring. Significant non-carcinogenic risks existed in both winter and spring with more severe health risks in winter, and Mn caused significant non-carcinogenic risks. The health risks in winter were mainly influenced by Zhengzhou and surrounding cities and long-distance transport in the northwest, and the health risks in spring were mainly influenced by Zhengzhou and surrounding cities.

Insight Study of Trace Elements in PM2.5 During Nine Years in Delhi, India: Seasonal Variation, Source Apportionment, and Health Risks Assessment.

This study investigated the concentrations, seasonal variations, sources, and human health risks associated with exposure to heavy elements (As, Al, Pb, Cr, Mn, Cu, Zn, and Ni) of PM2.5 at an urban location of Delhi (28° 38' N, 77° 10' E; 218m amsl), India, from January 2013 to December 2021. The average mass concentration of PM2.5 throughout the study period was estimated as 127 ± 77µgm-3, which is exceeding the National Ambient Air Quality Standards (NAAQS) limit (annual: 40µgm-3; 24h: 60µgm-3). The seasonal mass concentrations of PM2.5 exhibited at the order of post-monsoon (192 ± 110 µgm-3) > winter (158 ± 70 µgm-3) > summer (92 ± 44 µgm-3) and> monsoon (67 ± 32 µgm-3). The heavy elements, Al (1.19µgm-3), Zn (0.49µgm-3), Pb (0.43µgm-3), Cr (0.21µgm-3), Cu (0.21µgm-3), Mn (0.07µgm-3), and Ni (0.14µgm-3) exhibited varying concentrations in PM2.5, with the highest levels observed in the post-monsoon season, followed by winter, summer, and monsoon seasons. Six primary sources throughout the study period, contributing to PM2.5 were identified by positive matrix factorization (PMF), such as dust (paved/crustal/soil dust: 29.9%), vehicular emissions (17.2%), biomass burning (15.4%), combustion (14%), industrial emissions (14.2%), and Br-rich sources (9.2%). Health risk assessments, including hazard quotient(HQ), hazard index(HI), and carcinogenic risk(CR), were computed based on heavy elements concentrations in PM2.5. Elevated HQvalues for Cr and Mn linked with adverse health impacts in both adults and children. High carcinogenic risk values were observed for Cr in both adults and children during the winter and post-monsoon seasons, as well as in adults during the summer and monsoon seasons. The combined HIvalue exceeding one suggests appreciable non-carcinogenic risks associated with the examined elements. The findings of this study provide valuable insights into the behaviour and risk mitigation of heavy elements in PM2.5, contributing to the understanding of air quality and public health in the urban environment of Delhi.

Impact of COVID-19 Lockdown on Inhaled Toxic Elements in PM2.5 in Beijing: Composition Characterization and Source-Specific Health Risks Assessment

In early 2020, China experienced a mass outbreak of a novel coronavirus disease (COVID-19). With an aim to evaluate the impact of emission variations on toxic element species in PM2.5 and the health risks associated with inhalation exposure during COVID-19, we collected PM2.5 filter samples in Beijing from January 1 to February 28, 2020. Positive matrix factorization (PMF) and a health risk (HR) assessment model were used to assess the health risks of the toxic elements and critical risk sources. The total concentration of eight toxic elements (Se, Cd, Pb, Zn, As, Cu, Ni, and Cr) in Beijing showed a trend of first increasing and then decreasing: full lockdown (322.9 ng m−3) > pre-lockdown (264.2 ng m−3) > partial lockdown (245.3 ng m−3). During the lockdown period, stringent control measures resulted in significant reductions (6−20%) in Zn, Pb, Cd, and Ni levels, while concentrations of Se, As, Cu, and Cr were unexpectedly elevated (14−348%). A total of five sources was identified: traffic emission, coal combustion, dust emission, industrial emission and mixed source of biomass burning and firework combustion. Total carcinogenic risk (TCR) of the selected toxic elements exceeded the US EPA limits for children and adults. As and Cr (IV) were the main contributors to non-carcinogenic and carcinogenic risks, respectively. For source-resolved risks, coal combustion was the main contributor to HI (43%), while industrial emissions were the main cause of TCR (45%). Additionally, increased contributions from coal combustion, biomass burning, and firework combustion during the full lockdown elevated the HI and TCR values.

Chemical composition and trajectories of atmospheric particles at the Machu Picchu Peruvian Antarctic scientific station (62.09º S, 58.47º W)

Antarctica is a remote and relatively pristine region, but the regional transport of aerosols may be a source of pollution, especially in the Antarctic Peninsula. Few studies have characterized atmospheric aerosols and evaluated the contribution of their emission sources. The Peruvian Antarctic research station Machu Pichu (ECAMP, by its Spanish acronym) is located on King George Island in the Antarctic Peninsula. During February 2020, atmospheric particulate mass (PM10 and PM2.5) was sampled and analyzed to characterize its elemental composition and was supplemented by measurements of equivalent black carbon and aerosol size distributions. Chemical elements were analyzed by inductively coupled plasma mass spectrometry (ICP-MS), multivariate techniques, and enrichment factors. The most abundant elements in PM10 and PM2.5 were Na, Fe, Mg, and Si, with the most important local sources being marine (Na, Mg, Mn, Ca) and crustal (Fe, Al, P). Sources of weathering (Ba and Si) from glacial thawing and sources of combustion linked to the use of oil (V) and emission of black carbon were recorded. Air mass back-trajectory analysis using the HYSPLIT model helped identify external sources of particulate matter in the air masses reaching the ECAMP site. Overall, this study supports the growing evidence of the anthropogenic impact of distant and local sources on the white continent.

Characterization of Metal Elements in Atmospheric PM2.5 and Health Risk Assessment in Heze in Winter from 2017 to 2018

Atmospheric PM2.5 samples were collected in Heze, Shandong Province, from a total of three sampling sites at Heze College, Huarun Pharmacy, and a wastewater treatment plant between October 15, 2017 and January 31, 2018, to determine the concentrations of 21 metal elements in PM2.5 using inductively coupled plasma mass spectrometry (ICP-MS). The degree of elemental enrichment was also discussed, the health risks and potential heavy metal ecological risks were assessed. The results showed that ρ (PM2.5) ranged from 26.7 to 284.1 μg·m-3 at the three sampling sites during the sampling period, and the concentration values did not differ significantly, all of which were at high pollution levels. The highest concentrations of K were found in the three sampling sites, accounting for 31.03%, 39.47%, and 38.43% of the total, respectively, mainly due to the high contribution of biomass burning in autumn and winter in Heze, a large agricultural city. The highest concentrations of Zn, 89.70, 84.21, and 67.68 ng·m-3, were found in the trace elements at the three sampling sites, respectively. The enrichment factor results showed that the enrichment factor values of Zn, Pb, Sn, Sb, Cd, and Se were higher than 100, among which the enrichment factors of Cd and Se were higher than 2 000 and 4 000, respectively, which were significantly influenced by anthropogenic activities and might have been related to industrial production, metal smelting, road sources, and coal combustion emissions. The health risk results showed that there was some potential non-carcinogenic risk (HQ>0.1 for children and adults) for As and a combined potential non-carcinogenic risk (HI>0.1) and some potential carcinogenic risk (CRT>1×10-6) for both children and adults at the three sampling sites. There was a more significant carcinogenic risk (CRT>1×10-4) for adults at the wastewater treatment plant, and the slightly higher carcinogenic risk for adults than that for children may have been related to the longer outdoor activity and higher PM2.5 exposure for adults. The elements with the highest potential ecological risk values were Cd, As, and Pb, with Cd exhibiting a very high potential ecological risk that should be taken seriously. All three sampling sites showed a very high combined potential ecological risk, with the intensity spatially expressed as Heze College>Huarun Pharmacy>wastewater treatment plant.

Source and respiratory deposition of trace elements in PM2.5 at an urban location in Dhaka city

Air pollution has been creating severe environmental crises in Dhaka. This city ranks at the top among the major cities of the world. A multidimensional study is needed to assess the severity of this crisis. This study aims to determine the sources of trace elements in PM2.5 and their effects on health. We measured concentrations of 15 trace elements in PM2.5 every hour for eight days using a well-equipped mobile air quality monitoring system integrated with an automatic sampling system (AQMS, Horiba, Japan). We analyzed the concentrations of the trace elements to identify their potential sources and diurnal variation and to compute the respiratory deposition dose of the trace elements to estimate the health risks they pose. The daily average concentration of PM2.5 was higher than the allowable limit set by the World Health Organization (WHO). Among the trace elements, sulfur had the highest concentration and vanadium was the lowest. We found out that concentrations of the elements were the highest during the middle of the day and the lowest during midnight. Four source profiles of PM2.5 were identified by positive matrix factorization (PMF). Soil dust with sulfur-rich petroleum contributed about 65 %, industrial and non-exhaust emissions about 5 % each, and heavy engine oil combustion about 25 % to air pollution. Air mass backward trajectory analysis indicated that Dhaka's air contains both local and transboundary pollution. According to the determined respiratory deposition dose of the elements, males had higher deposition than females during heavy exercise. Sulfur and vanadium have the highest and lowest respiratory deposition dose, respectively. The highest amount of deposition occurred in the upper airways. We expect that this study will help professionals develop effective strategies to prevent and mitigate the emission of air pollutants.

Evaluating PM2.5 element concentration measurements for a nationwide monitoring network

ABSTRACT Particulate matter (PM) concentrations have decreased dramatically over the past 20 years, thus lower method detection limits (MDL) are required for these measurements. Energy-dispersive X-ray fluorescence (XRF) spectroscopy is used to quantify multiple elements simultaneously in the U.S. Environmental Protection Agency (EPA) Chemical Speciation Network (CSN). Inductively-coupled plasma mass spectrometry (ICP-MS) is an alternative analysis with lower MDL for elements. Here, we present a side-by-side comparison of XRF and ICP-MS for elements in PM2.5 samples collected via the EPA’s CSN. For ICP-MS, a simple extraction and ICP-MS analysis technique was applied to a wide variety of samples to minimize effort and cost and serve as a feasibility test for a large monitoring network. Filter samples (N = 549) from various urban locations across the US were analyzed first analyzed via XRF at UC Davis and then ICP-MS at RTI International. Both methods measured 29 of the same elements out of the 33 usually reported to CSN. Of these 29, 14 elements (Na, Mg, Al, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Pb) were found to be frequently detected (i.e. had more than 10% of values above both XRF and ICP-MS MDL). ICP-MS was found to have lower MDL for 26 out of 29 elements, namely Na, Mg, Al, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, As, Se, Rb, Sr, Zr, Ag, Cd, In, Sn, Sb, Cs, Ba, Ce, Pb; conversely, XRF had lower MDL for 3 elements, namely, P, K, Zn. Intra-method quality checks using (1) inter-elemental inspection of scatter plots using a priori knowledge of element sources and (2) scatter plots of routine versus collocated measurements reveal that ICP-MS exhibits better measurement precision. Lower detection limits for element measurements in nationwide PM monitoring networks would benefit human-health and source apportionment research. Implications: We demonstrate that ICP-MS with adilute-acid digestion method would significantly improve the element detection rates and thus be avaluable addition to the current analysis techniques for airborne PM samples in anationwide monitoring network. In this paper, we show that a hybrid method of elemental analysis for airborne particulate matter (PM) would significantly improve the detection rates for elements in PM. This would be a valuable addition to the current analysis techniques for airborne PM samples in nationwide and other large-scale monitoring networks, such as the EPA’s Chemical Speciation Network (CSN). The techniques explored in this study (i.e., X-ray Fluorescence Spectroscopy or XRF and Inductively Coupled Plasma-Mass Spectrometry or ICP-MS) are relevant to the PM monitoring and regulatory community audience of JAWMA, especially agencies and states that are already involved in CSN. In addition, our results outline considerations that give insight on factors to consider for other large-scale and long-term ambient air monitoring efforts.

Temporal and Spatial Variations of Potentially Toxic Elements in PM10 Collected in Jeddah City, Saudi Arabia.

Air pollution causes environmental and health problems around the world. In this study, ambient particulate matter with an aerodynamic diameter equal to or less than 10 microns (PM10) has been collected at three different locations in Jeddah city, Saudi Arabia. The locations are characterized by differences in terms of traffic, residential intensity, industrial, and non-road mobile machinery activities. The monthly and annual mass concentration of the PM10 exceeds the recommended annual limit of the World Health Organization (15 µg/m3) and the European air quality standard (40 µg/m3) at the three locations. The collected PM10 samples as well as a certified reference material of atmospheric particulates (NIST 1678a) were digested in aqua regia using microwave digestion. The quantitative elemental analysis was carried out using inductively coupled plasma mass spectrometry. The variations of the elemental concentration in terms of workdays, weekends, seasons, and annual were determined at the three locations. The spatial and temporal elemental variations were found to be different between the three sites, pointing to local influences that should be further evaluated. The concentration of Cd was found to be high and may cause health problems.

Contributions of the oil sands sources to the ambient concentrations and deposition of particulate elements in the Canadian Athabasca oil sands region

In this study, model sensitivity tests were conducted to investigate the relative contributions between emission sources of oil sands (OS) activities and other sources to the ambient concentrations and deposition of 29 particulate elements in the Athabasca oil sands region (AOSR) of Canada. Element emission sources from a recently developed emission database were grouped into three source sectors for elements in PM2.5 (OS-Industrial, OS-Dust, and Non-OS) and two source sectors for elements in PM2.5–10 (OS-All and Non-OS). The OS-Dust and OS-Industrial sectors (combined as one sector for PM2.5–10; OS-All) included element sources linked to dust and other industrial activities from the OS activities, respectively, whereas the Non-OS sector included remaining sources in the region, unrelated to the OS activities. The OS-Industrial, OS-Dust, and Non-OS emissions (tonnes/year) of all elements in PM2.5 were 326, 1430, and 562, respectively. The OS-All and Non-OS emissions (tonnes/year) of all elements in PM2.5–10 were 5890 and 2900, respectively. The element concentrations were simulated by the CALPUFF dispersion model. The sum of the domain averaged annual mean concentrations of all elements in PM2.5 and PM2.5–10 from all sources were 57.3 ng/m3 and 30.4 ng/m3, respectively. Except for Co (PM2.5 and PM2.5–10), Sb (PM2.5–10), and Sn (PM2.5–10), major proportions (≥ 59 %) of the ambient concentrations of the individual elements were linked to the OS source sector. Overall, the OS sector was responsible for 78 % and 68 % of the sum of the mean ambient concentrations of all elements in PM2.5 and PM2.5–10, respectively, which are close to the corresponding emission contributions (76 % and 67 %, respectively). Likewise, the bulk proportion (∼74 %) of the sum of the total atmospheric deposition of all elements was also associated with the OS sources. Carcinogenic and non-carcinogenic risks associated with inhalation exposure to airborne elements were below the recommended threshold risk levels.

Spatial distributions of PM10-bound metal elements in the central part of western Taiwan and their potential emission sources and the carcinogenic health risks.

This study aimed to investigate the spatial distribution of metal elements in PM10 and their potential sources and associated health risks over a period of two years in eight locations in the central part of western Taiwan. The study revealed that the mass concentration of PM10 and the total mass concentration of 20 metal elements in PM10 were 39.0 μg m-3 and 4.74 μg m-3, respectively, with total metal elements accounting for approximately 13.0% of PM10. Of the total metal elements, 95.6% were crustal elements (Al, Ca, Fe, K, Mg, and Na), with trace elements (As, Ba, Cd, Cr, Co, Cu, Ga, Mn, Ni, Pb, Sb, Se, V, and Zn) contributing only 4.4%. Spatially, the inland areas exhibited higher PM10 concentrations due to lee-side topography and low wind speeds. In contrast, the coastal regions exhibited higher total metal concentrations because of the dominance of crustal elements from sea salt and crustal soil. Four primary sources of metal elements in PM10 were identified as sea salt (58%), re-suspended dust (32%), vehicle emissions and waste incineration (8%), and industrial emissions and power plants (2%). The positive matrix factorization (PMF) analysis results indicated that natural sources like sea salt and road dust contributed up to 90% of the total metal elements in PM10, while only 10% was attributed to human activities. The excess cancer risks (ECRs) associated with As, Co, and Cr(VI) were greater than 1 × 10-6, and the total ECR was 6.42 × 10-5. Although only 10% of total metal elements in PM10 came from human activities, they contributed to 82% of the total ECR.

PM2.5 at a semi‐rural site near Beijing, China

AbstractBreathing clean air is a human right still not accessible to everyone. In most of the world, the air is polluted, which affects both the environment and human health. To investigate the air pollution situation in a semi‐rural part of northern China, particles with a diameter below 2.5 μm (PM2.5) were collected in Changping, 40 km northwest of Beijing in May and June 2016. The particles were analyzed for mass, trace elements, and black carbon (BC). The mean PM2.5 mass was 49 μg/m3, ranging from 3.1 to 266 μg/m3. S, Cl, K, Ca, Ti, V, Mn, Fe, Ni, Cu, Zn, As, and Pb were determined by Energy Dispersive X‐Ray Fluorescence (EDXRF). They constituted 4% of the PM2.5 mass, with BC adding another 3%. Enrichment factor evaluation identified S, Ni, Cu, Zn, As, and Pb as the main anthropogenic contributors to environmental impact. A pollution load index (PLI) of 0.03 showed that the site could not be considered as polluted by the trace elements in PM2.5. Positive matrix factorization (PMF) was used for source apportionment of the PM2.5 content. The PMF analysis reveals that a mixture of mineral dust, fossil fuel combustion, industries, and salts were the main sources of air pollution. The non‐carcinogenic and carcinogenic health risks were assessed, and both show a small health risk in the short study period. Following the development of PM2.5 concentrations over time in this part of China shows a decreasing trend of PM2.5 pollution, which is promising for the future.

Characteristics and health risk assessments of fine particulate matter at the overground and underground subway sites in Chengdu

Fine particulate matter (PM2.5) associated with toxic components in the subway system is likely to lead to various diseases, which has raised public concern, but it has not been explored deeply. Therefore, this study aimed to reveal the characteristics and health effects of the PM2.5 in the subway system. The PM2.5 samples were collected from ticket counters, platforms, and carriages in the overground and underground subway systems in Chengdu, and the composition of PM2.5 at different sites was detected. The pollution degree of toxic elements in PM2.5 and the health risks were evaluated. The results showed that the concentrations of PM2.5, some elements (e.g., arsenic, barium, chromium, copper, iron, manganese, nickel, and antimony), and total carbon at the underground sites were higher than those at the corresponding overground sites, respectively. The pollution extent at underground sites was more severe than that at overground sites according to pollution load index. The subway workers had potential non-carcinogenic risks. The total cancer risks for subway workers were at a moderate level, and for passengers were at a low level in most conditions. The contributions of arsenic to the hazard index and total cancer risk were 74.22%–81.5% and 79.4%–85.3%, respectively. Overall, underground platforms and carriages were the locations with the highest health risks for subway workers and passengers respectively. Subway workers faced higher health risks than passengers and arsenic was identified as the predominant risk element. These results provide basic data for future subway air quality improvement.

Exploring Sources and Health Risks in Beijing PM2.5 in 2019 and 2020

The various industries, sectors, and citizens’ daily lives have undergone significant changes after the outbreak of the COVID-19 pandemic. The researchers collected and analyzed PM2.5 samples including secondary inorganic ions (SO42−, NO3−, and NH4+, namely SNA), organic carbon (OC), elemental carbon (EC), and other 16 metal elements in Beijing in 2019 (before the pandemic) and 2020 (after the pandemic). The particulate matter (PM2.5) concentration in the autumn and winter of 2020 is 21.16 µg/m3 and 14.05 µg/m3 lower than in 2019, respectively. The contribution of six sources of pollution, including coal combustion, secondary sources, transportation-related sources, dust, Industrial I, and Industrial II, were analyzed using the Positive Matrix Factorization (PMF) model. Due to the impacts of the COVID-19 pandemic, more and more people are choosing private transportation, such as private cars, instead of public transportation. As a result, the contribution of PM2.5 pollution related to transportation increased after the pandemic. The metal elements measured during the sampling period represent only a very small fraction (1%) of PM2.5. However, their health risk to humans cannot be ignored because of the toxicity of some metallic elements, and the carcinogenic risks induced by metal elements in PM2.5 exceeded the safety threshold (>10−6) during the autumn and winter of 2019 and 2020. Arsenic (As) contributes the most to carcinogenic risk, so controlling arsenic emissions is the primary approach to reducing cancer risk in Beijing. Considering the contribution to the health risk from various sources obtained in PMF, coal combustion is the most significant contributor to cancer risk. Therefore, serious consideration should be given to controlling coal combustion at the local and regional levels to reduce health risks in Beijing.