Levels and human health risk assessment of heavy metals in surface soil of public parks in Southern Ghana

Assessment of occupational health risk due to inhalation of chemical compounds in an aircraft maintenance, repair, and overhaul company

This study was conducted in an aircraft maintenance, repair, and overhaul (MRO) company in 2021 to identify the extent of occupational exposures and quantitative assessment of the health risk due to inhalation of chemical compounds. According to the inspection of different parts of this company, heavy metals including Co, Cd, Ni, Pb, Cr(VI), and Mn and organic compounds including benzene, toluene, ethylbenzene, xylene (BTEX), and methyl ethyl ketone (MEK) were selected for health risk assessment. In total, the air in the inhalation area of active workers was sampled in 51 workstations. Measurement of the above pollutants showed that the average occupational exposure to Cd, Pb, and all organic compounds fell within the acceptable range of occupational exposure standard, while the measured values for Co, Ni, Mn, and Cr(VI) exceeded the standard limit. According to calculations, the highest carcinogenic risk (CR) was seen in the plating (airplane) workshop for exposure to Cr(VI) (7.58E-01), and the lowest CR was observed in the electronic workshop for exposure to Pb (7.75E-08). The highest non-carcinogenic hazard (HQ) was found in the welding workshop for exposure to Co (1.00E + 04), while the lowest HQ was related to toluene in the fabrication workshop (9.10E-03). Considering the high rate of exposure indicators, CR and HQ exceeded the standards set by the American Environmental Protection Agency (EPA) in most workshops. Accordingly, company managers should take the necessary measures to reduce the vulnerability of individuals working in areas with unacceptable CR and HQ.

Contamination Assessment and Potential Human Health Risks of Heavy Metals in Urban Soils from Grand Forks, North Dakota, USA

Heavy metal (HM) pollution of soil is an increasingly serious problem worldwide. The current study assessed the metal levels and ecological and human health risk associated with HMs in Grand Forks urban soils. A total 40 composite surface soil samples were investigated for Mn, Fe, Co, Ni, Cu, Zn, As, Pb, Hg, Cr, Cd and Tl using microwave-assisted HNO3-HCl acid digestion and inductively coupled plasma mass spectrometry (ICP-MS) analysis. The enrichment factor (EF), contamination factor (CF), geoaccumulation index (Igeo), ecological risk and potential ecological risk index were used for ecological risk assessment. The park soils revealed the following decreasing trend for metal levels: Fe > Mn > Zn > Cr > Ni > Cu > Pb > As > Co > Cd > Tl > Hg. Based on mean levels, all the studied HMs except As and Cr were lower than guideline limits set by international agencies. Principal component analysis (PCA) indicated that Mn, Fe, Co, Ni, Cu, Zn, As, Cd, Pb, Cr and Tl may originate from natural sources, while Hg, Pb, As and Cd may come from anthropogenic/mixed sources. The Igeo results showed that the soil was moderately polluted by As and Cd and, based on EF results, As and Cd exhibited significant enrichment. The contamination factor analysis revealed that Zn and Pb showed moderate contamination, Hg exhibited low to moderate contamination and As and Cd showed high contamination in the soil. Comparatively higher risk was noted for children over adults and, overall, As was the major contributor (>50%), followed by Cr (>13%), in the non-carcinogenic risk assessment. Carcinogenic risk assessment revealed that As and Cr pose significant risks to the populations associated with this urban soil. Lastly, this study showed that the soil was moderately contaminated by As, Cd, Pb and Hg and should be regularly monitored for metal contamination.

Source apportionment of soil heavy metals: A new quantitative framework coupling receptor model and stable isotopic ratios

Tracing the source of heavy metals in soils is crucial for reversing the worrisome situation of heavy metal contamination. In this study, the origins of heavy metal pollution in soil were examined in a primary electronic waste treatment and disposal hub in China, using a synergistic source apportionment framework consisting of the positive matrix factorization (PMF) model and the Bayesian stable-isotope analysis mixing model (MixSIAR). Industrial activity is significant to heavy metal contamination in both industrial park and farmland soils, however, the contribution varied through PMF model (industrial park, 64.2%; farmland, 35.6%). In the industrial park, Pb was identified as the major pollutant in the soils, and the local children suffered from noncarcinogenic risks. Moreover, the contribution of Pb contamination sources were allocated more accurately (electronic waste dismantling, 25.1%; industrial production, 23.7%; vehicle exhaust from leaded gasoline, 9.1%; vehicle exhaust from unleaded gasoline, 20.2%; natural process, 21.9%) using MixSIAR for the first time. The main soil contaminants in surrounding farmland were Cd, Cu, and Zn. The variations in heavy metal pollution sources in soils were found to be associated with local policies and regulations, such as the phasing out of leaded gasoline and the conversion of industrial park from electronic waste demolition switched to production and storage. The identification of the source of heavy metals in soil will support targeted reduction of the associated emissions, which can immediately help alleviating soil contamination and control human health risks.

Human health risk-based soil environmental criteria (SEC) for park soil in Beijing, China

Urban parks are important places that allow urban residents to experience nature but are also associated with the risk of exposure to contaminated soil. Therefore, it is necessary to establish appropriate soil environment criteria (SEC) to manage park soil quality. Studies on the demographic characteristics and behavioral patterns of urban park visitors are helpful for the selection of sensitive receptors and the determination of parameters in the establishment of SEC. This study explored the park visitors' demographic characteristics and behavioral patterns, and applied the results to derive SEC. Eighty-six parks in Beijing were selected, and mobile phone data were obtained to analysis the demographic characteristics and residence time of the visitors. Kruskal-Wallis test, kernel density estimation and random forest model were used for data analysis. The CLEA model was used to derive SEC. The results showed that the demographic characteristics and behavioral patterns of visitors in different types of parks were quite different. Parks were mostly used by males and visitors aged 31-45. Most visitors stayed in the park for 1-2 h, and the distance from a given visitor's home to the park was the most important factor affecting stay time. Then, several parameters such as the parameters related to the receptors and occupation period were optimized, and the SEC of sensitive parks and non-sensitive parks were derived. Exposure frequency may be the main reason for the difference of SEC between the two types of parks. The SECs of sensitive parks were higher than the soil screening values (SSVs) for class 1 land in GB36600-2018, indicating that the current SSVs for some parks may be too conservative. This study provides a reference for the formulation and revision of soil environmental standards for park land, and suggests strengthening research on human behavioral patterns.

Human Activity in Antarctica: Effects on Metallic Trace Elements (MTEs) in Plants and Soils

Colobanthus quitensis (Kunt) is one of the two vascular plant species present in Antarctica and develops under severe environmental conditions, being found in both pristine and human-threatened environments. We determined the Cd, Cr, Cu, Mn, Ni, Pb, and Zn levels in C. quitensis roots, leaves, and soils of origin using flame atomic absorption spectroscopy. In January 2017, we collected samples from four geographical zones on the longitudinal gradient along which C. quitensis is distributed, starting from Punta Arenas (PAR) at the extreme south of mainland Chile and moving southwards to the Antarctic territory from King George Island (KGI) to Hannah Point Peninsula (PHA) and finally Lagotellerie Island (LAT). We used certified reference material to validate the plant tissues and soil samples we collected. The highest concentrations of metals that we measured in the soils and in the C. quitensis roots and leaves were in samples we collected at the KGI station, the zone with the greatest human activity. The lowest concentrations we measured were at the LAT station, an island with little human intervention and scarce fauna. The mean concentrations of metals in the roots and leaves of C. quitensis followed a similar order at all sampling locations: Mn > Zn > Cu > Ni > Pb > Cr > Cd. In contrast, in soil, they followed the following order: Mn > Zn > Cu > Cr > Pb > Ni > Cd. The concentration levels obtained for the different metals in the soil and plants tissue samples in this region of Antarctica indicated that the area was non-polluted. However, the metallic trace element (MTE) concentrations may be at an early stage of contamination, as described in other areas of the Antarctic, being a new threat to this continent.

Spatiotemporal distribution and human health risk assessment of potential toxic species in soils of urban and surrounding crop fields from an agricultural area, Córdoba, Argentina

The spatiotemporal distribution of potentially toxic species was studied in the topsoil of parks, playgrounds, and surrounding crop fields of Marcos Juarez City in Córdoba province, Argentina. The content of available metals and of some pesticides used in the region was determined. The mean values of available metal concentrations in all samples, expressed in mg kg^-1, were 7.99 ± 6.58, 0.89 ± 0.71, 0.35 ± 0.26, and 1.50 ± 1.40 for Pb, Cr, Cd, and Ni, respectively. Pearson's correlation coefficients, coefficient of variation (%), and principal component analysis were used to explore whether variations in metal content were associated with anthropogenic factors. Agrochemicals such as lindane, chlorobenzilate, endosulfan, endrin, permethrin, and chlorpyrifos were found in crop field soil samples. In turn, chlorothalonil, chlordanes, methoxychlor, DDT, permethrin, and chlorpyrifos were detected in park and playground soil samples. The degree of pollution with possible effects on environmental health was evaluated using the Nemerow integrated pollution index (NIPI) and the modified degree of contamination (mCd). In some campaigns, the values obtained from crop fields ranged from low to high pollution levels during periods of agrochemical application. Noteworthy, in periods of low agrochemical application in crop fields, a high level of pollution was observed in parks and playgrounds. For children, the hazard index (HI) values were higher than the threshold value of 1, suggesting a potential health risk. This study provides valuable information regarding land management practices and highlights the importance of monitoring and implementing policies to reduce human health risks.

Level, source, and risk assessment of toxic elements in traditional agricultural soils and coping strategies

The level, source, and risk of toxic elements in traditional agricultural soils are particularly crucial for the sustainable development of agriculture. An important agricultural production base was selected, a total of 251 topsoil samples were collected, eight toxic elements (As, Cd, Cr, Cu, Hg, Ni, Pb, Zn) in soil were analyzed, and environmental and health risk assessments were conducted. Results showed that all concentrations of eight elements in soil samples were lower than the risk screening values with negligible pollution risk. Approximately 83.8% of Hg in soil was originated from atmospheric deposition related to industrial emissions, 53.2% of Cd was derived from direct industrial activities, and the other elements came from soil parent materials or agricultural activities. Accumulation risk of As in agricultural products, potential ecological risk from Cd, and As's ingestion risk and Cr's dermal contact risk should be paid more attention. More stricter monitoring and coping countermeasures and strategies should be established to ensure the sustainable development of agriculture.

MAPK/iNOS pathway is involved in swine kidney necrosis caused by cadmium exposure

Cadmium (Cd) pollution in the environment could cause toxic damage to animals and humans. MAPK pathways could regulate their downstream inflammatory factors, and plays a crucial role in necrosis. Since the swine kidney tissue is an important accumulation site of Cd and target organ of its toxic damage, but the damage form of Cd to swine kidney and the role of MAPK pathways in it are still not clear, we selected six week old weaned piglets as the research object, and fed a diet supplemented CdCl₂ (20 mg/kg) to establish the model of liver injury induced by Cd. The expressions and phosphorylation of MAPK pathways (ERK, JNK, p38), expression levels of inflammatory factors (TNF-α, NF-κB, iNOS, COX-2 and PTGE) and necrosis related genes (MLKL, RIPK1, RIPK3 and FADD) and heat shock proteins (HSPs) were detected by RT-PCR and Western blot. H.E. staining was used to determine the damage of kidney caused by Cd exposure. The results showed that Cd exposure could activate p38 and JNK pathway phosphorylation, rather than ERK 1/2, up regulated the expressions of inflammatory factors, finally induced programmed necrosis (increasing the expressions of MLKL, RIPK1, RIPK3 and FADD) in swine kidney. Our study elucidated the mechanism of Cd-damage to swine kidney and the relationship among MAPK pathways, inflammatory factors and programmed necrosis in swine.

Relationship between Urban Green Spaces and Cancer: A Scoping Review

This scoping study aims to explore the relationships between urban green spaces (UGSs) and the onset, remission and recovery of cancer. We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) extension for scoping reviews (protocol published in 2018). Eligibility criteria for papers were: (1) to be concerned with UGSs, (2) reporting effects of UGSs on cancer-related outcomes including direct or indirect measures, (3) reporting randomized controlled trials, prospective cohort studies, case studies, observational studies, non-comparative studies, (4) in English or French. The search covered primary studies in the published and unpublished (grey) literatures searching by hand and electronic databases (MEDLINE, Green File, Cumulative Index to Nursing and Allied Health Literature and ScienceDirect). Among 1703 records screened by two reviewers independently, 29 were included for qualitative synthesis. We classify the cancers concerned and the effects reported i.e., protective effect, risk or without association. The most investigated cancers are bladder, breast and lung cancer. Our study also identified contributing factors and their mediating effects between UGSs and cancer. Even though the strength of the evidence of the associations between UGSs and cancer is still weak due to the low number of studies and their design, results highlight the wide variety of possible mediating factors between the use of green spaces and cancer occurrence, remission and/or prevention. Knowledge gaps and future research perspectives should be oriented to qualitative research on protective factors with an attention to equity in UGS access and use.

Risk assessment of potentially toxic elements in soils and vegetables around coal-fired thermal power plant: a case study of Dhanbad, India

The present study was intended to determine the potentially toxic elements (PTEs) concentration in fly ash (FA), soil, plant, and vegetable to assess the impacts of pollution on the nearby areas of coal-fired thermal power plant (TPP). The PTEs concentrations (mg/kg) in FA were Cr (48-74) > Pb (41-65) > Cd (7.4-9.7) > As (3.19-4.43) > Hg (0.518-0.598). The contamination factor (C_f) for Cd was highest in agricultural soil (C_f = 22) followed by roadside soil (C_f = 20), and forest soil (C_f = 15), which showed that the soil was strongly polluted due to the presence of Cd. The ecological risk index (ERI) in the topsoil of roadside area was also very high (1130), due to the high value of ecological risk factor of Cd (898) and Hg (213). The health risk associated with the intake of soil containing PTEs were also estimated by calculating hazard index (HI), and the values showed that the risk posed to children was minimum (HI < 1). But in case of roadside area, the HI was very close to one (0.975) indicating that the prolong exposure may pose severe health risk. The bioaccumulation coefficient of all PTEs for Albizia lebbeck and Madhuca longifolia were < 1, indicating less PTEs accumulation in the plant species. The hazard quotient of all PTEs (except of Hg) through vegetable consumption (Allium cepa and Raphanus sativus) was > 1, which signifies that the long-time consumption of contaminated vegetables may cause severe risk to the people.

Quantifying Source Apportionment, Co-occurrence, and Ecotoxicological Risk of Metals from Upstream, Lower Midstream, and Downstream River Segments, Bangladesh

The positive matrix factorization (PMF) receptor model was used for the first time to quantify the source contributions to heavy metal pollution of sediment on a national basin scale in the upstream, midstream, and downstream rivers (Teesta and Kortoya-Shitalakkah and Meghna-Rupsha and Pasur) of Bangladesh. The metal contamination status, co-occurrence, and ecotoxicological risk were also investigated. Sediment samples were collected from 30 sites at a depth range of 0 to 20 cm for analysis of 9 metals using inductively coupled plasma-mass spectrometry. The mean concentrations of metals varied for upstream, lower midstream, and downstream river segments. The results showed that chromium (Cr) exhibited a strong significant co-occurrence network with other metals (e.g., manganese [Mn], iron [Fe], and nickel [Ni]). Monte Carlo simulation results of the geo-accumulation index (Igeo; 63.3%) and risk indices (48.5%) showed that cadmium (Cd) was the main contributor to sediment pollution. However, the cumulative probabilities of sediments being polluted by metals were ranked as "moderate to heavily polluted" (Igeo 46.6%; risk index 16.7%). Toxicity unit results revealed that zinc (Zn) and Cd were the key toxic contributors to sediments. The PMF model predicted metal concentrations and identified 4 potential sources. The agricultural source (factor 1) mostly contributed to copper (Cu; 78.9%) and arsenic (As; 62.8%); Ni (96.9%) and Mn (83.5%) exhibited industrial point sources (factor 2), with 2 hot spots in northwestern and southwestern regions. Cadmium (93.5%) had anthropogenic point sources (factor 3), and Fe (64.3%) and Cr (53.5%) had a mixed source (factor 4). Spatially, similar patterns between PMF apportioning factors and predicted metal sources were identified, showing the efficiency of the model for river systems analysis. The degree of metal contamination in the river segments suggests an alarming condition for biotic components of the ecosystem. Environ Toxicol Chem 2020;39:2041-2054. © 2020 SETAC.

Cadmium Pollution in the Tourism Environment: A Literature Review

Cadmium is a highly-toxic metal, and, its environmental occurrence and human exposure consequently deserve close attention. The insight into the relationships between cadmium and tourism relations has deepened during the past three decades and the research into this relationship is reviewed. For this purpose, 83 relevant publications (mainly articles in international journals) were analyzed. It was found that investigation of Cd in the tourism environment took place in all continents (except Antarctica) and has intensified since the mid-2000s; Chinese researchers are the most active contributors. The Cd occurrence in air, living organisms, sediments, soil, suspended particular matter, water, and of the human environment has been studied. It has become clear that tourism contributes to Cd pollution (particularly, by hotel wastewater and increased traffic), and, vice versa, Cd pollution of beaches, coastal waters, food, urban parks, etc. creates risks for tourists and increases human exposure to this toxic metal. Both mechanisms have received equal attention. Examples concern many places worldwide, with the Mediterranean and Central and Eastern Europe as apparently critical regions. Our significantly incomplete knowledge of the relationships between cadmium and tourism must be ascribed to the common oversimplification of these relationships and to the scarcity or even absence of information supplied by the most important tourist destinations. The present review demonstrates that more studies of heavy metals and, particularly, Cd in the tourism environment are needed.