Residents health risk of Pb, Cd and Cu exposure to street dust based on different particle sizes around zinc smelting plant, Northeast of China

Source-specific probabilistic risk evaluation of potentially toxic metal(loid)s in fine dust of college campuses based on positive matrix factorization and Monte Carlo simulation

Contamination, hazard level and source of 10 widely concerned potentially toxic metal(loid)s (PTMs) Co, As, Pb, Cr, Cu, Zn, Ni, Mn, Ba, and V in fine dust with particle size below 63 μm (FD63) were investigated to assess the environmental quality of college campuses and influencing factors. PTMs sources were qualitatively analyzed using statistical methods and quantitatively apportioned using positive matrix factorization. Probabilistic contamination degrees of PTMs were evaluated using enrichment factor and Nemerow integrated enrichment factor. Eco-health risk levels of content-oriented and source-oriented for PTMs were evaluated using Monte Carlo simulation. Mean levels of Zn (643.8 mg kg-1), Pb (146.0 mg kg-1), Cr (145.9 mg kg-1), Cu (95.5 mg kg-1), and Ba (804.2 mg kg-1) in FD63 were significantly larger than soil background values. The possible sources of the concerned PTMs in FD63 were traffic non-exhaust emissions, natural source, mixed source (auto repair waste, paints and pigments) and traffic exhaust emissions, which accounted for 45.7%, 25.4%, 14.5% and 14.4% of total PTMs contents, respectively. Comprehensive contamination levels of PTMs were very high, mainly caused by Zn pollution and non-exhaust emissions. Combined ecological risk levels of PTMs were low and moderate, chiefly caused by Pb and traffic exhaust emissions. The non-cancer risks of the PTMs in FD63 to college students fell within safety level, while the carcinogenic PTMs in FD63 had a certain cancer risks to college students. The results of source-specific health risk assessment indicated that Cr and As were the priority PTMs, and the mixed source was the priority pollution source of PTMs in FD63 from college campuses, which should be paid attention to by the local government.

Assessment of sources, environmental, ecological, and health risks of potentially toxic elements in urban dust of Moscow megacity, Russia

Potentially toxic elements (PTEs) in urban dust of Moscow megacity and related risks have been studied. 78 samples were collected in the Moscow downtown in sites with different anthropogenic load, namely, major highways, residential area, and recreation zones. The concentrations of PTEs in urban dust were determined by ICP-MS and ICP-AES. Then, environmental, ecological and health risks of PTEs in urban dust were assessed. In addition, potential sources of PTEs in dust were identified. It is shown that Moscow dust is mainly contaminated by Sb, Zn, Pb, Cd, Cu, Sn, and Mo, which according to the data of principal component and correlation analyses can be attributed to anthropogenic sources (non-exhaust vehicle emissions). Potential ecological risk factor demonstrates that Cu, Mo, and Cd have moderate potential ecological risks in 13% of studied area, while Sb has this risk in 62% of area. Potential ecological risk indices indicate that 41% of studied territory is of moderate ecological risk. Concerning the human risks through ingestion, dermal contact, and inhalation pathways, PTEs in Moscow dust have no significant non-carcinogenic risks for adults. However, the value of total hazard index for children is 1.8 showing that non-carcinogenic risks may occur. Moreover, possible carcinogenic risks caused by Cr are evaluated. The finding of the present study can be used for ecological management in the megacity to reduce both ecological and human risks. A special attention should be given to periods of hot and dry weather and to traffic-related emissions.

Spatial distribution, pollution level, and health risk of Pb in the finer dust of residential areas: a case study of Xi'an, northwest China

The spatial distribution, pollution level, and exposure risk of Pb in the finer dust (particle size < 63 μm) of residential areas in Xi'an, northwest China were investigated in this study. Geographical information systems and geodetector methods were used to analyze the spatial variability of Pb content in the finer dust of Xi'an and its forming mechanism. The enrichment factor was used to assess the extent of Pb pollution, and the hazard index was used to evaluate the health risks to children and adults exposed to Pb. The results showed that the average content of Pb in the finer dust of residential areas in Xi'an was 99.9 mg kg^-1. In the Xi'an urban area, a higher Pb content was mainly found in the finer dust near the Second Ring Road of Xi'an City, and the Pb content in the old town of Xi'an City was relatively lower than that near the Second Ring Road. The results of geodetector analysis indicate that the spatial variability of Pb in the finer dust of the Xi'an urban area was primarily controlled by the interaction among vehicle emissions, daily behavior of residents, and industrial emissions. Pb in the finer dust from residential areas in all districts showed moderate enrichment. The non-cancer risks of Pb in the finer dust were within the safe range for both children and adults. However, the prolonged exposure risk of Pb in the finer dust of residential areas should be considered for children.

Impact of particle sizes on health risks and source-specific health risks for heavy metals in road dust

To analyze the impact of particle sizes on sources and related health risks for heavy metals, road dust samples in Beijing were collected and sifted into five particle sizes. The positive matrix factorization (PMF), human health risk assessment model (HHRA), and Monte Carlo simulation were used in the health risk assessment and source apportionment. Results showed that mass of particles < 74 μm occupied about 50% of the total particles, while only 8.48% of the particles were > 500 μm. Mass distribution and concentrations of heavy metals in each particle size changed in temporal. Over 85.00% of carcinogenic risks (CR) were from particles <74 μm, whereas CR from particles >250 μm were ignorable. Sources for health risks in each particle size were traffic exhaust, fuel combustion, construction, and use of pesticides and fertilizers. Proportions of sources to CR differed among particle sizes. Traffic exhaust and fuel combustion contributed over 90% to CR in particles <74 μm, whereas construction contributed the highest (31.68-54.14%) among all sources in particles 74-250 μm. Furthermore, the difference between health risks based on sifted road dust and that based on unsifted road dust was quantitatively analyzed. Source-specific health risk apportionment based on unsifted road dust was not presentative to all particle sizes, and true value of health risks could be over 2.5 times of the estimated value based on unsifted road dust, emphasized the importance of sifting of road dust.

Trends, Issues and Future Directions of Urban Health Impact Assessment Research: A Systematic Review and Bibliometric Analysis

Health impact assessment (HIA) has been regarded as an important means and tool for urban planning to promote public health and further promote the integration of health concept. This paper aimed to help scientifically to understand the current situation of urban HIA research, analyze its discipline co-occurrence, publication characteristics, partnership, influence, keyword co-occurrence, co-citation, and structural variation. Based on the ISI Web database, this paper used a bibliometric method to analyze 2215 articles related to urban HIA published from 2012 to 2021. We found that the main research directions in the field were Environmental Sciences and Public Environmental Occupational Health; China contributed most articles, the Tehran University of Medical Sciences was the most influential institution, Science of the Total Environment was the most influential journal, Yousefi M was the most influential author. The main hotspots include health risk assessment, source appointment, contamination, exposure, particulate matter, heavy metals and urban soils in 2012–2021; road dust, source apposition, polycyclic aromatic hydrocarbons, air pollution, urban topsoil and the north China plain were always hot research topics in 2012–2021, drinking water and water quality became research topics of great concern in 2017–2021. There were 25 articles with strong transformation potential during 2020–2021, but most papers carried out research on the health risk assessment of toxic elements in soil and dust. Finally, we also discussed the limitations of this paper and the direction of bibliometric analysis of urban HIA in the future.

Characteristics of PM2.5 in an Industrial City of Northern China: Mass Concentrations, Chemical Composition, Source Apportionment, and Health Risk Assessment

Urban and suburban PM_2.5 samples were collected simultaneously during selected periods representing each season in 2019 in Zibo, China. Samples were analysed for water-soluble inorganic ions, carbon components, and elements. A chemical mass balance model and health risk assessment model were used to investigate the source contributions to PM_2.5 and the human health risks posed by various pollution sources via the inhalation pathway. Almost 50% of the PM_2.5 samples exceeded the secondary standard of China's air quality concentration limit (75 µg/m³, 24 h). Water-soluble inorganic ions were the main component of PM_2.5 in Zibo, accounting for 50 ± 8% and 56 ± 11% of PM_2.5 at the urban and suburban sites, respectively. OC and OC/EC decreased significantly in the past few years due to enhanced energy restructuring. Pearson correlation analysis showed that traffic emissions were the main source of heavy metals. The Cr(VI) concentrations were 1.53 and 1.92 ng/m³ for urban and suburban sites, respectively, exceeding the national ambient air quality standards limit of 0.025 ng/m³. Secondary inorganic aerosols, traffic emissions, and secondary organic aerosols were the dominant contributors to PM_2.5 in Zibo, with the total contributions from these three sources accounting for approximately 80% of PM_2.5 and the remaining 20% attributed to traffic emissions. The non-carcinogenic risks from crustal dust for children were 2.23 and 1.15 in urban and suburban areas, respectively, exceeding the safe limit of 1.0 in both locations, as was the case for adults in urban areas. Meanwhile, the carcinogenic risks were all below the safe limit, with the non-carcinogenic and carcinogenic risks from traffic emissions being just below the limits. Strict control of precursor emissions, such as SO₂, NOx, and VOCs, is a good way to reduce PM_2.5 pollution resulting from secondary aerosols. Traffic control, limiting or preventing outdoor activities, and wearing masks during haze episodes may be also helpful in reducing PM_2.5 pollution and its non-carcinogenic and carcinogenic health impacts in Zibo.

Adverse health and environmental outcomes of cycling in heavily polluted urban environments

Cycling is a healthy habit; however, are its benefits outweighing risks when biking in heavily trafficked and air-polluted cities? Research involved studying contamination with traffic-related elements of dust collected from bike paths located in top trafficked cities of Europe in Poland. Human health risk was assessed via inhalation and ingestion pathways for adults and children. Bike path dust was heavily contaminated with Zn, Cd (Geoaccumulation index Igeo 4) and Pb (Igeo 3), sourced predominantly from nonexhaust car emissions. The concentrations of metals in dust decreased in the following descending order: Zn > Mn > Cu > Pb > Cr > Cd. A fractionation study revealed that Zn and Cd are almost entirely bioavailable (Mobility factor MF above 90%), causing hazards to humans and the environment. The highest congested intersections result in more TRAP-contaminated dust deposited on bike paths, which is easily resuspended, posing a health risk for cyclists or pedestrians. Avoiding cycling in proximity to heavily trafficked routes should be considered, when possible, as well as physical removal of dust by wet sweeping to limit dust resuspension.

Exposure of street sweepers to cadmium, lead, and arsenic in dust based on variable exposure duration in zinc smelting district, Northeast China

Street dust is an important contributor to heavy metal exposure in street sweepers. In this work, the levels of cadmium (Cd), lead (Pb), and arsenic (As) in street dust were evaluated, and the corresponding health implications for street sweepers in the smelting district of Huludao city northeast China were assessed. The contributions of dietary sources and dust to total metal exposure in street sweepers were compared. Because street sweepers are exposed to street dust both during work and nonwork hours, the health risks faced by street sweepers are uncertain. Therefore, variable exposure duration was considered using a deterministic model. A probabilistic risk assessment model was developed to explore the health effects of street dust on street sweepers via Monte Carlo simulation. The various exposure parameters that affect risk were analyzed using sensitivity analysis. The average Cd, Pb, and As levels in the hair of street sweepers were 2.04, 20.12, and 0.52 mg·kg^-1, respectively. These values were higher than those for residents (i.e., not street sweepers) of Huludao. Strong correlations were found between the logarithms (base 10) of the Cd, Pb, and As contents in dust and hair (r_Cd = 0.581, p < 0.01; r_Pb = 0.428, p < 0.01; r_As = 0.378, p < 0.01; n = 62). Based on analysis using deterministic models, the maximum exposures to Cd and Pb via dust through the alimentary canal were nearly three and six times higher than the dietary exposures, respectively. Sensitivity analysis indicated that exposure duration is an important parameter.

Plasma vitrification and heavy metals solidification of MSW and sewage sludge incineration fly ash

Thermal plasma treatment has been considered as one of promising methods for fly ash disposal. In this study, firstly, the characteristics of municipal solid waste incineration (MSWI) fly ash and sewage sludge incineration (SSI) fly ash were analyzed, followed by the raw material formulations of low melting temperature determined by thermodynamic equilibrium calculation. Then verified experiments were carried out by thermal plasma system, focused on the formation condition of vitrified slags with various CaO-SiO₂-Al₂O₃ ratios and the influence factors of heavy metals (Cd, Cr, Ni, Pb, Zn, Cu) transference. According to the results: During the co-treatment process of fly ashes, a lower temperature of vitrified slag formation as low as 1230 ℃ was observed. Vitrification is determined by the molten phase content during melting process, the correlation coefficient between the glass phase content of slag and the molten phase content was 0.81 (P < 0.01). CaO content of raw materials was a major element for the volatilization of Cd and Pb. High Al₂O₃ content can remain more Cr, Cu and Ni in slags, but it is not conducive to the solidification of Zn. The synthetic toxicity index of heavy metals would greatly reduce from 23153.15 to 663.29-820.63 after thermal plasma treatment.

Analyzing environmental risk, source and spatial distribution of potentially toxic elements in dust of residential area in Xi'an urban area, China

A comprehensive study on concentration, spatial distribution, pollution, ecological-health risk and source of potentially toxic elements (PTEs) in dust of residential area in Xi'an, China were conducted to explore the environmental quality of residential area in urban district. The results show that the concentrations of V, Ni, and Mn in the dust were less than, while the contents of Cr, Zn, Pb, Cu, and Ba in the dust were obviously larger than, the soil background values of Shaanxi. The high-value area of PTEs primarily concentrated in densely populated areas, heavily trafficked areas and the surroundings of plants. Cr, Pb and Zn posed moderate enrichment and Pb possessed moderate ecological risk in the dust. The comprehensive pollution levels of PTEs in the dust were uncontaminated to moderately contaminated and their comprehensive ecological risk were moderate. The non-carcinogenic risks of the PTEs for adults and children were in the safe level and the carcinogenic risks of Ni and Cr were under the current acceptable value. Four major sources were discriminated on basis of the multivariate statistical analysis results and the content characteristics, enrichment degrees, and the spatial distribution features of the PTEs, viz. Mn, V, and Ni primarily came from natural source; Pb, Zn, and Cu mainly originated from traffic source; and Ba and Cr were respectively from construction source and coal-fired power plant source, which respectively contributed 22.8%, 28.3%, 47.3%, and 1.6% to the total content of PTEs determined in the dust.

Metallic elements in human hair from residents in smelting districts in northeast China: Environmental factors and differences in ingestion media

The health of residents in Huludao City is affected by the emissions of heavy metals from smelting, diet and atmospheric precipitation. This study investigated the concentrations of Hg, Cd, Pb, Cu and Zn in scalp hair samples from 259 residents of different ages and genders from five districts in Huludao City and examined the main factors for heavy metal exposure. Cd and Pb concentrations in hair samples exceeded the normal concentration ranges for human hair (Cd < 0.3 mg/kg; Pb < 9.3 mg/kg), and the highest Pb concentrations were found in subjects in the age range 0-15 years. Samples from men were higher in Cd and Pb compared to those for women. Workers from the Huludao zinc plant (HZP) had higher concentrations of all metals in their hair relative to other occupations except for Cu. Geographically, the highest Cd and Pb concentrations in hair were found for residents living in Daochi district (DCD) and the Zn plant district (ZPD), respectively. In smelting regions, the effects of dust ingestion on heavy metal exposure were more important than in non-smelting regions.

Effects of soil particle size on metal bioaccessibility and health risk assessment

Oral ingestion is the main exposure pathway through which humans ingest trace metals in the soil, particularly for children. Metals in different soil particle size fractions may vary in terms of concentration and properties. Urban school/kindergarten soil samples were collected from three cities: Lanzhou in northwest China, Wuhan in central China, and Shenzhen in southeast China. Soil samples were classified according to particle size (<63 μm, 63-150 μm, 150-250 μm, and 250-2000 μm) to estimate the effects of soil particle size on the total content and bioaccessibility of metals (Cd, Cr, Cu, Ni, Pb, and Zn). Based on the results, we assessed whether the standard size <150 μm (containing < 63 μm and 63-150 μm), recommended by the Technical Review Workgroup (TRW) of the Environmental Protection Agency (EPA), and <250 μm (containing < 63 μm, 63-150 μm, and 150-250) recommended by the Bioaccessibility Research Group of Europe (BARGE), are suitable where the largest proportion adhering to hands is the finest soil (<63 μm). The results showed that different metals exhibited different relationships between soil particle size and content and between soil particle size and bioaccessibility. Pb and Zn generally exhibited the greatest bioaccessibility in the coarsest particle sizes (250-2000 μm); whereas the highest Ni bioaccessibility occurred in the finest sizes (<63 μm); the bioaccessibility of other metals did not exhibit any obvious relationships with particle size. When assessing health risks using bioaccessible metal content in the recommended soil particle size ranges (<150 μm and <250 μm) and in finer particles (<63 μm), the results for noncarcinogenic risks to children exhibited no obvious difference, while the actual carcinogenic risks may be underestimated with the use of soil particle size ranges < 150 μm and <250 μm. Therefore, when choosing an optimal particle size fraction to evaluate the health risk of oral soil ingestion, we recommend the use of the bioaccessible metal content in <63 μm soil fraction.

An integrated study of health, environmental and socioeconomic indicators in a mining-impacted community exposed to metal enrichment

The occurrence of toxic metals and metalloids associated with mine tailings is a serious public health concern for communities living in mining areas. This work explores the relationship between metal occurrence (e.g., spatial distribution in street dusts), human health indicators (e.g., metals in urine samples, lifestyle and self-reported diseases) and socioeconomic status (SES) using Chañaral city (in northern Chile) as study site, where a copper mine tailing was disposed in the periurban area. This study model may shed light on the development of environmental and health surveillance plans on arid cities where legacy mining is a sustainability challenge. High concentrations of metals were found in street dust, with arsenic and copper concentrations of 24 ± 13 and 607 ± 911 mg/kg, respectively. The arsenic concentration in street dust correlated with distance to the mine tailing (r = - 0.32, p-value = 0.009), suggesting that arsenic is dispersed from this source toward the city. Despite these high environmental concentrations, urinary levels of metals were low, while 90% of the population had concentrations of inorganic arsenic and its metabolites in urine below 33.2 µg/L, copper was detected in few urine samples (< 6%). Our results detected statistically significant differences in environmental exposures across SES, but, surprisingly, there was no significant correlation between urinary levels of metals and SES. Despite this, future assessment and control strategies in follow-up research or surveillance programs should consider environmental and urinary concentrations and SES as indicators of environmental exposure to metals in mining communities.

Human Health Risk Assessment associated with contaminants in the finest fraction of sidewalk dust collected in proximity to trafficked roads

The objective of the study was to determine concentration of metals in sidewalk dust collected in close vicinity to heavily congested roads in Poland in order to assess non-carcinogenic and carcinogenic health risk for both children and adults associated with the ingestion, dermal contact and inhalation of sidewalk dust. Results revealed that sidewalk dust from Warsaw, Krakow, Wroclaw and Opole is heavily contaminated especially with Sb, Se, Cd, Cu, Zn, Pb, considered as indicators of traffic emission. Hazardous indices determined for different exposure pathways indicated that the greatest health risk for both children and adults is associated with the ingestion of sidewalk dust. Carcinogenic risk associated with the ingestion of sidewalk dust by children, calculated for As, Cd, Ni and Pb exceeded safe level of 1 × 10^-4 in all cities except for Warsaw. Non-carcinogenic risk of ingestion for children was two orders of magnitude higher than dermal risk and four to five orders of magnitude higher than risk of inhalation. Non-carcinogenic risk associated with the ingestion of sidewalk dust by adults is comparable with dermal contact risk and five orders of magnitude higher when inhalation risk.

History metal (Pb, Zn, and Cu) deposition and Pb isotope variability in multiple peatland sites in the northern Great Hinggan Mountains, Northeast China

Placer gold mining is important anthropogenic sources of dust and metals that can strongly influence the environmental quality of the surrounding ecosystem. However, scarce studies have focused on evaluating the influence of placer gold mining on historical metal deposition in the surrounding ecosystem in the northern Great Hinggan Mountains, which is located at northeast of China. To address this research gap, four peatland cores with different distances to a gold placer in the northern Great Hinggan Mountains were selected in this study. Based on the ²¹⁰Pb depth-age model, historical variations in the Pb isotope and deposition fluxes of Pb, Cu, and Zn were reconstructed. The results show that metal deposition in the northern Great Hinggan Mountains was mainly influenced by the placer gold mining around the 1900s when the gold placer started to produce gold, and placer gold mining more seriously influenced the western sites that were closer to the placer gold mining. With increasing global metal productions after 1930, the proportion of the metals from placer gold mining sources gradually decreased, and part of Pb were transported via the atmosphere from other regions (e.g., Europe, East Asia). With the implementation of environmentally friendly policies and the decreasing anthropogenic production of Pb, Cu, and Zn around the world, deposition fluxes of these metals in the northern Great Hinggan Mountain began to decrease after 2000.

Chemical speciation, pollution and ecological risk of toxic metals in readily washed off road dust in a megacity (Nanjing), China

Pollution of potentially toxic metals (PTMs) in road dust (RD) is becoming an important threat to the urban environmental quality and human health. The chemical speciation of PTMs is an important index charactering the risks, which may also closely relate to the pollution level and source but it was poorly understood. In this study, the chemical speciation of Cd, Cr, Cu, Ni, Pb and Zn in the RD of a megacity (Nanjing), China was determined following an optimized BCR (proposed by the European Community Bureau of Reference) sequential extraction procedure to assess their pollution and potential eco-risk and to explore the variations of metal chemical speciation with the pollution levels and sources. Total concentrations of the PTMs in the RD were enriched 1.4- to 123-fold relative to the subsoil with median contamination factors (CF) of 6.7 (Pb), 6.0 (Cu), 5.5 (Cd), 4.0 (Zn), 2.0 (Cr) and 1.9 (Ni). Pollution of the PTMs should be mainly from industrial and traffic emissions and showed high CF values in the northern industrial zone. Whereas, the chemical percentages of each metal showed relatively narrow spatial variations and were not statistically correlated with the pollution levels (p = 0.05). Comparing of similar studies indicates that no regular patterns existed in chemical percentages for each metal in RD polluted by the traffic and/or both the industrial and traffic sources. In the RD of Nanjing, Pb was mostly associated with reducible phase, Cd and Zn were mainly present in acid-soluble phase, Cu was mostly concentrated in oxidizable phase, while Cr and Ni were predominantly present in residual phase. As the typical pollutants, anthropogenic Cd, Cu, Pb and Zn were mostly associated with the potential mobile phases but also with the residual phase in the RD of Nanjing, causing 1.4- to 3.0-fold increase in the mobility. Combining the assessments from eco-risk index, risk assessment code and sediment quality guidelines with the pollution levels and chemical speciation, we deduced that Cd, Cu, Pb and Zn may pose certain eco-risk upon transport into the aquatic system and soil, and Cd should be primarily concerned.

Pollution and ecological risk assessment of nutrients associated with deposited sediments collected from roof and road surfaces

Surface-deposited sediment in urban areas is an essential environmental medium for assessing nutrient contamination. The total nitrogen (TN) and total phosphorus (TP) pollution associated with surface-deposited sediments can be transported into urban water bodies by runoff and can cause eutrophication of those water bodies. By analyzing the samples collected on roof surfaces and road surfaces, this study provides a comparison of the differences in TN and TP pollution loading in sediments on these two different impervious surface materials. Also, an assessment of the ecological risk of nutrients in surface-deposited sediments with respect to grain size fraction was performed. The results indicate that the TN and TP pollution loading in both road-deposited sediments and roof-deposited sediments indicated an asymmetric "W" trend along with grain size fraction, and both road-deposited sediments and roof-deposited sediments had the highest TN and TP pollution contribution when the particle size is between 250 and 500 μm. TN in roof-deposited sediments has high ecological risk when the particle size is less than 250 μm. These findings help to provide guidance for the management of surface-deposited sediment pollution.

Chemical fractionation and mobility of traffic-related elements in road environments

Due to considerable progress in exhaust control emission technology and extensive regulatory work regarding this issue, non-exhaust sources of air pollution have become a growing concern. This research involved studying three types of road environment samples such as road dust, sludge from storm drains and roadside soil collected from heavily congested and polluted cities in Poland (Krakow, Warszawa, Opole and Wroclaw). Particles below 20 µm were examined since it was previously estimated that this fine fraction of road dust is polluted mostly by metals derived from non-exhaust sources of pollution such as brake linings wear. Chemical analysis of all samples was combined with a fractionation study using BCR protocol. It was concluded that the finest fractions of road environment samples were significantly contaminated with all of the investigated metals, in particular with Zn, Cu, both well-known key tracers of brake and tire wear. In Warszawa, the pollution index for Zn was on average 15-18 times the background value, in Krakow 12 times, in Wroclaw 8-12 times and in Opole 6-9 times the background value. The pollution index for Cu was on average 6-14 times the background in Warszawa, 7-8 times in Krakow, 4-6 times in Wroclaw and in Opole 5 times the background value. Fractionation study revealed that mobility of examined metals decreases in that order: Zn (43-62%) > Cd (25-42%) > Ni (6-16%) > Cu (3-14%) > Pb (1-8%). It should, however, be noted that metals even when not mobile in the environment can become a serious health concern when ingested or inhaled.

Grain Size Distribution and Health Risk Assessment of Metals in Outdoor Dust in Chengdu, Southwestern China

A total of 27 outdoor dust samples from roads, parks, and high spots were collected and analyzed to investigate the contamination of 11 metals (Cr, Mn, Co, Ni, Cu, Zn, As, Sr, Cd, Sb, and Pb) in Chengdu, China. The results showed that the samples from the high spots exhibited the highest heavy metal level compared with those from the roads and the parks, except for Ni, Cu, and Pb. The dust was classified into five grain size fractions. The mean loads of each grain size fraction of 11 determined metals displayed similar distribution, and the contribution of median size (63-125, 125-250, 250-500 μm) fractions accounted for more than 70% of overall heavy metal loads. The health risk posed by the determined metals to human via dust ingestion, dermal contact, and inhalation was investigated. Oral and respiratory bioaccessible parts of the metals in dust were extracted using simulated stomach solution and composite lung serum. The mean bioaccessibilities of 11 investigated metals in the gastric solution were much higher than those in the composite lung serum, especially Zn, Cd, and Pb. Ingestion was the most important exposure pathway with percentage greater than 70% for both children and adults. Risk evaluation results illustrated that children in Chengdu might suffer noncarcinogenic risk when exposed to outdoor dust. Given that the cancer risk values of Pb and Cr larger than 1 × 10(-4), potential carcinogenic risk might occur for Chengdu residents through outdoor dust intake.

Social Structural Influences on Healthy Aging: Community-Level Socioeconomic Conditions and Survival Probability of Becoming a Centenarian for Those Aged 65 to 69 in South Korea

This study estimated the associations between community-level socioeconomic conditions and survival probability of becoming a centenarian (SPBC) for those aged 65 to 69 in South Korea to determine the social structural influences on healthy aging. The indicators of socioeconomic and data of centenarians were obtained from Statistics Korea database 2014: population census and social survey. Significant positive correlations were found between SPBC and community-level socioeconomic conditions (minimum cost of living and economically active population, water supply and sewerage, pave a road with asphalt, and urbanization). SPBC male and female predictors had higher economic level and base facilities (R2)=0.578, p<.001). The study provides evidence that community-level socioeconomic conditions are important correlates of SPBC for those aged 65 to 69 in South Korea. These strategies should include social structural influences on successful aging in the overall socioeconomic conditions.

A comparative study of the grain-size distribution of surface dust and stormwater runoff quality on typical urban roads and roofs in Beijing, China

The deposition of pollutants on impervious surfaces is a serious problem associated with rapid urbanization, which results in non-point-source pollution. Characterizing the build-up and wash-off processes of pollutants in urban catchments is essential for urban planners. In this paper, the spatial variation and particle-size distributions of five heavy metals and two nutrients in surface dust were analyzed, and the runoff water first-flush effect (FF30) and event-mean concentrations (EMCs) of 10 common constituents were characterized. The relationships between runoff variables and stormwater characteristics were examined from three typical urban impervious surfaces in Beijing, China. Dust on road surfaces with smaller grain sizes had higher pollutant concentrations, whereas concentrations of Mn, Zn, Fe, and TP in roof surface dust increased with grain size. Particles with grain sizes of 38-74 and 125-300 μm contributed most to the total pollutant load in roads, while particles with the smallest grain sizes (<38 μm) contributed most on roofs (23.46-41.71 %). Event-mean concentrations (EMCs) and FF30 values for most runoff pollutants tended to be higher on roofs than on roads. The maximum intensity (I max) and the antecedent dry days (ADD) were critical parameters for EMCs in roads, while ADD was the only dominant parameter for EMCs on our studied roof. The rainfall intensity (RI) and maximum intensity (I max) were found to be the parameters with the strongest correlation to the first-flush effect on both roads and roofs. Significant correlations of total suspended solids (TSS) concentration in runoff with grain-size fractions of surface dust indicated that coarser particles (74-300 μm) are most likely to contribute to the solid-phase pollutants, and finer particles (<38 μm) are likely the main source of dissolved pollutants.