USEPA Model Research Articles

Atmospheric gaseous mercury and associated health risk assessment in the economic capital of India.

Mercury cycling in coastal metropolitan areas on the west coast of India becomes complex due to the combined effects of both intensive domestic anthropogenic emissions and marine air masses. The present study is based on yearlong data of continuous measurements of gaseous elemental mercury (GEM) concentration concurrent with meteorological parameters and some air pollutants at a coastal urban site in Mumbai, on the west coast of India, for the first time. The concentration of GEM was found in a range between 2.2 and 12.3ng/m3, with a mean of 3.1 ± 1.1ng/m3, which was significantly higher than the continental background values in the Northern Hemisphere (~ 1.5ng/m3). Unlike particulates, GEM starts increasing post-winter to peak during the monsoon and decrease towards winter. July had the highest concentration of GEM followed by October, and a minimum in January. GEM exhibited a distinct diurnal cycle, mainly with a broad peak in the early morning, a narrow one by nightfall, and a minimum in the afternoon. The peaks and their timing suggest the origin of urban mobility and the start of local activities. A positive correlation between SO2, PM2.5, temperature, relative humidity, and GEM indicates that emissions from local industrial plants in the Mumbai coastal area. Principal component analysis (PCA) and cluster analysis (CA) confirm this fact. Monthly back trajectory analysis showed that air mass flows are predominantly from the Arabian Sea and local human activities. Assessment of human health risks by USEPA model reveals that the hazardous quotient, HQ < 1, implies negligible carcinogenic risk. GEM observations in Mumbai during the study period are below the World Health Organization's (WHO) safe limit (200ng/m3) for long-term inhalation.

Radiological Safety Assessment of Tailings Extracted from Kaolin Mining Sites in Katsina State

This research was carried out to sufficiently justify the recent increased awareness and concern for the potential hazards associated NORMs in the environment of the research around Kankara and Dutsin-ma Kaolin mining sites Katsina State; Nine (09) Kaolin samples were collected randomly from the mining sites for the study. The radioactivity analysis was done experimentally using NaI(TI) gamma spectrometer at Center for energy research and training, Ahmadu Bello University Zaria. The health hazards were evaluated using numerous radiological, Statistical and USEPA models. The overall hazard index (HI) was found to be 1.496609 for children found in third sampling point of Yar-goje are; it is the only possibility of a children to be affected while 0.799486 for adults, this value was below the USEPA threshold limit for non-carcinogenic risks of 1.0 indicating that the exposed population ages are unlikely to experience any adverse non-carcinogenic risks. The radiological parameters obtained are 226Ra (238U), 232Th and 40K of a NORMs with activity concentration of is 100.889, 0.129 and 224.040 (Bqkg-1) in the soil samples, at the studied area. Absorbed frequency in air measured in nGy/h by one-meter directly above the crushed, was considered, since the forbidding radioactivity concentrations is obtained as 77.575 while the total annual effective dose (AED) in mSv/y had average value of 0.099 in soil. The values obtained for external and internal radiological hazard indices Hext and Hint are 0.471 and 0.741 in soil; which were lower than the UNSCEAR suggested boundary limit of unity. Lastly, the overall excess lifetime cancer menace owed to NORMs, stood as 5.63E-06 and 4.15E-06 for whole populations indicating that (a maximum of 6 people/1 million may be affected) for adults while (a maximum of 4 people /1 million may be affected) for children. These values were within the USEPA threshold of 1E-04.

Biogeochemical behavior, health risk assessment and source identification of antimony and arsenic in soil from a legacy antimony smelter in Gansu, Northwest China

The study of the contamination patterns and characteristics of Sb and As in the soils of the legacy contaminated sites of antimony smelters is important for the redevelopment and utilization of industrial sites. In this study, 13 heavy metals were determined in the soil and plants of an antimony smelter in Gansu Province to study the biogeochemical behavior, health risk, and pollution source. The results showed that the Nemerow index of Sb (728) exceeded the value of As (43.6) by 17.6 times, and the average geoaccumulation index (Igeo) of Sb and As were 10.1 and 1.97, respectively, categorized as extremely and moderately contaminated classes. Compared to As, Sb had a larger proportion of oxidizable fraction and a smaller proportion of reducible fraction (Fe/Mn oxides), suggesting that Sb possessed a higher content of organic matter and sulfide forms. Even though the bioaccumulation factor (BAF) for As was about 10 times higher than that for Sb, the accumulation of Sb in plants was not negligible. For the USEPA model, the mean hazard quotient (HQ) values of As by oral ingestion, dermal absorption, and inhalation accounted for 99.0%, 0.97%, and 0.0002% of the total, and 54.2%, 45.3%, and 0.51% for MEEPRC model, respectively. There were significant positive correlations between Sb, As, Zn, Se, Cd, and Ba (P < 0.05). The results of the source identification analysis revealed that antimony smelting, solid waste pollution, and natural origin were identified as the main pollution sources. The principal component analysis (PCA) and positive matrix factorization (PMF) methods differed by more than 20% in the analysis of the contribution of antimony smelting activities and solid waste pollution sources, suggesting the differences in the models themselves and in the uncertainty parameters chosen during the application.

Characteristics and pollution risks of Cu, Ni, Cd, Pb, Hg and As in farmland soil near coal mines

Heavy metal (loid) pollution poses a serious threat to the health and habitability of ecosystems worldwide. This study aims to investigate the concentration, pollution degree, pollution sources, and health risks of heavy metal (loid)s (HMs) in soil of Shanxi Province, China. The concentrations of Cu, Ni, Cd, Pb, Hg and As were measured by ICP-MS in 146 soil samples collected from agricultural land. The pollution degree and ecological risks of HMs were analyzed by variety of indexes, and the human health risks were assessed using the USEPA model. Results showed the average concentrations of Cu, Cd, Pb, Hg and As were 1.08, 1.15, 1.44, 1.50 and 1.25 times higher than the background values in the soil of investigated areas, respectively. The contamination factors revealed moderate pollution of Hg, Pb, As, Cd and Cu in the investigated areas, and the pollution load index indicated considerable contamination. The Nemerow index revealed low to severe contamination with HMs. The potential ecological risk of HMs indicates that Hg and Cd pose a moderate risk threat to the soil ecology. Coal mining was the primary sources of soil HMs identified by ACPS-MLR. Soil As (75.1%) and Ni (62.3%) were mainly derived from coal mining, Pb (73.1%) was from traffic emissions, and Hg (38.6%) originated from coal combustion. The health risks associated with these HMs due to soil exposure were within the acceptable levels for adults. The As concentration imposes the strongest effect based on the non-carcinogenic risk analysis in different exposed populations. In conclusion, the higher concentration of soil HMs moderately threatens soil ecology, but there was no significant human health risk found in the study. Furthermore, this study reveals the potential risk and sources of HMs in Shanxi Province, which is helpful for managing contaminated soil in the region.

Contamination of As, Cd, Cr, Hg and Pb in soils in Arica commune (Chile).

The objectives of this study are (a) to determine the background concentration of As, Cd, Cr, Hg and Pb in Arica commune; (b) to determine the degree of soil contamination in Arica city using environmental indices and (c) to evaluate the human health risk of these potentially toxic elements. In the rural area of Arica commune, 169 samples were taken and 283 samples were taken in the urban area of Arica city. Total concentrations of Cd, Pb and Cr were determined by EPA 3052 and EPA 6010 C. Mercury was determined by EPA 7473. Arsenic was determined by EPA 7061A. The available concentrations of As and Cr were determined by dilute hydrochloric acid and EPA 6010C. Environmental indices were applied for pollution and US EPA model was used to evaluate human health risk. Background concentrations were As 18.2, Cd 1.12, Cr 73.2, Hg 0.02 and Pb 11.8mgkg-1, respectively. Environmental indices show that soil samples are located between slightly contaminated to extremely contaminated. Human health risk analysis shows that children have higher levels of risk than adults. The analysis with available concentrations of As and Cr shows no carcinogenic risk for adults and children, but 81% and 98% of the samples were between 10-6 and 10-4, that means intermediate risk.

Health risk assessment of trace elements in the Tonle Sap Great Lake and the Tonle Sap River in Cambodia during the rainy season.

To investigate the potential health risk of trace elements in the Tonle Sap Great Lake system, lake (n = 37) and river (n = 14) water samples were collected and analyzed for 19 trace elements (Ag, Al, As, B, Ba, Cd, Co, Cr, Cu, Fe, Ga, Mn, Mo, Ni, Pb, Se, Tl, U and Zn) using inductively coupled plasma mass spectrometry. As a result, Cd was not detected in any river and lake water samples. Al, Fe and Mn in lake water exceeded the regulation limits of Cambodia, USEPA and WHO. Health risk assessment using the USEPA model indicated that male and female Cambodian residents are at minimal risk of non-carcinogenic effects from single and mixed trace elements through lake and river water consumption. Nevertheless, As, Tl, Co, Ba, Mn and Cr might pose high potential health risks to consumers which requires more attention. Therefore, regular monitoring and further studies are required to investigate the pollution trends and toxic behavior of these trace elements in the Tonle Sap Great Lake system.

The Toxicological Risk Assessment of Dermal Exposure of Patients Exposed to Lead and Cadmium Due to Application of Ointments with Marjoram Herb Extract (Majoranae herbae extractum).

Potential heavy metal impurities (HMI) in pharmaceuticals/pharmaceutical products/drugs based on plant raw materials (e.g., herbs) are an important problem in the pharmaceutical industry; however, there is a lack of scientific articles on the comprehensive toxicological risk assessment of HMI in ointment applied dermally. To make the appropriate toxicological risk assessment, we consider: (1) the raw results of the levels of lead and cadmium in the ointments (metal per kg of mass), (2) one-time administration of the applied ointment, (3) daily exposure of Pb and Cd in the applied ointments according to the maximum daily dose of applied pharmaceuticals, including transcutaneous penetration, (4) human health risk assessment based on the USEPA model, and 5) the margin of exposure (MoE). The raw results indicated that lead (7.05-101.78 µg/kg) and cadmium (0.32-0.81 µg/kg) were present in all samples. The levels of analyzed HMI (independently of the producer and declared composition) were similar. Pb and Cd contamination associated with daily doses met the standards of the ICH Q3D (R2) guide on elemental impurities in pharmaceuticals, including the cutaneous route of administration. Taking into account the daily amount of lead and cadmium (ointment, ug/day) the results were satisfactory, confirming the safety of marjoram herb extract ointments available in Polish pharmacies according to the ICH guideline Q3D (R2) on elemental impurities. The HQ values obtained for Pb and Cd in all samples were less than 1; therefore, exposure to these HMI would not cause a health risk based on the USEPA model strategy. Furthermore, the obtained values of MoE for Pb and Cd in ointments were above 100, so exposure to these elements would not cause a health risk based on the MoE-based strategy. The original contribution of this work is that this is the first study on the triple approach strategy to evaluate the safety of heavy metal impurities in traditional herbal medicinal products applied dermally in solid form (ointments with marjoram herb extract). The research is novel and has not been previously published; The proposed procedure includes transcutaneous penetration of heavy metal (Pb and Cd) impurities described for the first time in the literature.

CalBMP, a web-based modeling tool for evaluating pesticide offsite movement and best management practice scenarios in California agricultural land

Quantitative evaluation of best management practice (BMP) effectiveness can help stakeholders to make better watershed management decisions. However, such evaluations are always challenging as they require complex algorithms to simulate the relevant hydrological processes, crop growth and the corresponding pollutant transport pathways in order to evaluate potential BMPs and select the best one for the specific field conditions. In this study, a web-based interface (CalBMP) was developed to predict BMP effectiveness in California, focusing on pesticide modeling at the field scale. With built-in databases for soil, weather, crop, pesticides, and BMPs, users can run simulations for baseline and BMP scenarios using their site-specific field conditions by simply providing the field information, such as zip code, soil, crop management, and pesticide application data. CalBMP uses PRZM5 + , a USEPA model, to simulate pesticide transport and fate at the field edge. The CalBMP simulations were validated based on measurements from an alfalfa field study. The results indicated that the CalBMP interface could reasonably simulate the runoff and adsorbed pesticide loss leaving the field with default parameters from previously known field parameters or public databases. CalBMP underestimated sediment erosion, possibly due to uncertainties in field measurements or inaccurate simulation of the temporal distribution of flood irrigation. CalBMP is likely to underestimate pesticides with greater solubility, such as diuron, because PRZM5 + uses the simplified instantaneous equilibrium sorption model. In addition, a strawberry field study was adopted to demonstrate the capability of the CalBMP interface for simulating BMP effectiveness (pesticide reduction percentage in the main pathways) with easy-to-understand graphs and tables. The results indicated that users can easily compare and review the results from multiple scenarios, which could facilitate the decision-making process for mitigating the amount of active ingredient bifenthrin leaving the field. The CalBMP tool provides useful information on pesticide runoff potential and BMP selection at the field scale. With increasingly stringent regulations for water quality protection, CalBMP will add to the growers’ toolbox for minimizing the environmental impacts from their inevitable pesticide usage.

Assessment of Nickel and Arsenic Poisoning and Estimation of Cancer Risk from Kaolin Mining Sites in Dutsin-Ma and Kankara, Katsina State

This research was carried out to assess how poisonous are Nickel and Arsenic as heavy metals contaminated around Kankara and Dutsinma Kaolin mining sites. Nine (09) samples were collected randomly from the mining sites for the study. The analysis of such elements was done using Energy Dispersive X-ray Fluorescence {EDXRF} at Central Laboratory, Umaru Musa Yar-adua Universitty, Katsina, and The health hazards were evaluated using numerous Statistical and USEPA models. The result obtained was used to calculate the risk assessment of Nickel and Arsenic in the body via inhalation, ingestion, and body contact. In which the most associated environmental and health risk of priority have Their average concentrations as 20.02, 12.59, 54.03, 1344.4, 21.94, 140.00, and NA which is not identified element in the studied area. All results were below the USEPA threshold limit for non-carcinogenic risks of 1.0 indicating that the exposed population ages are unlikely to experience any adverse non-carcinogenic risks. The overall total excess lifetime cancer risk for heavy metals was 8.5555E-06 (a maximum of 9 people/1 million may be affected) for children and 7.5773E-05 (a maximum of 8 people /1 million may be affected) for adults. These values were within the USEPA threshold of 1E-04.

Insights into As accumulation in soil-groundwater-wheat-hair system of suburban farmland: Distribution, transfer and potential health risk

Health risks caused by arsenic (As) contamination in soils and its migration in environmental media have attracted much attention. In this study, suburban farmland of KF city in the ecotone of the Yellow River and Huaihe River Basin was taken as the research area. A series of samples including topsoils (246), profile soils (280), matched wheat grains (22 groups), groundwater (26) and human hair (355) were collected. As distribution and transfer in soil-groundwater-wheat-hair (SGWH) system in typical sites were explored, and comprehensive health risk of As in SGWH system was assessed based on US EPA model and local exposure parameters. The results showed that spatial distribution of total As presented a significant high value area, and higher As contents (in the range of 0.45–29.86 mg kg−1) and bioavailability was mainly in topsoils, which indicated that anthropogenic sources have led to As enrichment in studied area. Also, it was found that the As contents in 95 % of wheat grain samples were higher than that in the control soils, and 9 % groundwater samples were above national Class I standards. Especially, average As content in hair in typical sites was obviously influenced by that in soil, wheat and groundwater. Moreover, As migration curve along soil → wheat (groundwater) → hair appeared an irregular ‘V’ shape, and transfer coefficients of Tf water/soil (10−5), Tf wheat/soil (10−3), Tf hair/soil (10−2), Tf hair/wheat (101) and Tf hair/water (104) presented an obvious increasing trend of magnitude, implying that human body has a higher As enrichment risk. Furthermore, comprehensive health risks for children and adults in typical sites were significant, while wheat is the main risk medium. In general, arsenic accumulation in human hair is good consistent with EPA health risk model, and their combination can better evaluate environmental exposure risk of As.

Herbicide spray drift from ground and aerial applications: Implications for potential pollinator foraging sources

A field spray drift experiment using florpyrauxifen-benzyl was conducted to measure drift from commercial ground and aerial applications, evaluate soybean [Glycine max (L.) Merr.] impacts, and compare to United States Environmental Protection Agency (US EPA) drift models. Collected field data were consistent with US EPA model predictions. Generally, with both systems applying a Coarse spray in a 13-kph average wind speed, the aerial application had a 5.0- to 8.6-fold increase in drift compared to the ground application, and subsequently, a 1.7- to 3.6-fold increase in downwind soybean injury. Soybean reproductive structures were severely reduced following herbicide exposure, potentially negatively impacting pollinator foraging sources. Approximately a 25% reduction of reproductive structures up to 30.5-m downwind and nearly a 100% reduction at 61-m downwind were observed for ground and aerial applications, respectively. Aerial applications would require three to five swath width adjustments upwind to reduce drift potential similar to ground applications.

A qualitative characterization of meso-activity factors to estimate soil exposure for agricultural workers

BackgroundAgricultural workers’ exposure to soil contaminants is not well characterized. Activity pattern data are a useful exposure assessment tool to estimate extent of soil contact, though existing data do not sufficiently capture the range and magnitude of soil contact in the agricultural context.ObjectiveWe introduce meso-activity, or specific tasks, to improve traditional activity pattern methodology. We propose a conceptual framework to organize the factors that may modify soil exposure and impact soil contact estimates within each meso-activity in agriculture. We build upon models from the US EPA to demonstrate an application of this framework to dose estimation.MethodsWe conducted in-depth interviews with sixteen fruit and vegetable growers in Maryland to characterize factors that influence soil exposure in agriculture. For illustrative purposes, we demonstrate the application of the framework to translate our qualitative data into quantitative estimates of soil contact using US EPA models for ingestion and dermal exposure.ResultsGrowers discussed six tasks, or meso-activities, involving interaction with soil and described ten factors that may impact the frequency, duration and intensity of soil contact. We organized these factors into four categories (i.e., Environmental, Activity, Timing and Receptor; EAT-R) and developed a framework to improve agricultural exposure estimation and guide future research. Using information from the interviews, we estimated average daily doses for several agricultural exposure scenarios. We demonstrated how the integration of EAT-R qualitative factors into quantitative tools for exposure assessment produce more rigorous estimates of exposure that better capture the true variability in agricultural work.SignificanceOur study demonstrates how a meso-activity-centered framework can be used to refine estimates of exposure for agricultural workers. This framework will support the improvement of indirect exposure assessment tools (e.g., surveys and questionnaires) and inform more comprehensive and appropriate direct observation approaches to derive quantitative estimations of soil exposure.Impact statementWe propose a novel classification of activity pattern data that links macro and micro-activities through the quantification and characterization of meso-activities and demonstrate how the application of our qualitative framework improves soil exposure estimation for agricultural workers. These methodological advances may inform a more rigorous approach to the evaluation of pesticide and other chemical and biological exposures incurred by persons engaged in the cultivation of agricultural commodities in soil.

Potential environmental pollution and human health risk assessment due to leachate contamination of groundwater from anthropogenic impacted site

One of the consequences of landfill systems is the emission of leachate, which is capable of causing contamination of the surrounding environment, including groundwater. Considering three major abandoned landfills in an urban area in Nigeria, the potential environmental pollution due to leachate generated from landfills and human health risk assessment of nearby groundwater were examined using laboratory standards (APHA 2012). The result revealed that the landfills' leachate pollution index (LPI) is 18.84, 19.57, and 19.66, indicating potential pollution of the environment, including groundwater and soil. Conformity of groundwater indicated that Arsenic (Ar-0.0001), Cadmium (Cd-0.002), Zinc (Zn-0.02), Barium (Ba-0.03), Manganese (Mn-0.05), Copper (Cu-0.02, 0.012), Chromium (Cr-0.006, 0.007), and Cobalt (Co-0.03, 0.015) are within the WHO permissible limit while Nickel (Ni-0.06) and Lead (Pb-0.05) exceeded the permissible limit. Using the USEPA model for human health risk assessment, the Total Hazard quotient (THQ) for ingestion and derma exposure indicated that the heavy metals have ≤1 across the three landfills, indicating that the exposed population experience no significant health risk. The THQ trended as Cd>Co>Zn>Ba>Mn>Cu>Cr>Ni>As>Pb for children across all the landfills. The estimation for Total Carcinogenic Risk (TCR) for carcinogenic metals (As, Cd, Cr, Ni, and Pb) from various landfill indicated no carcinogenic risk (TCR <10−6). Although the abandoned landfills showed potential environmental pollution and contamination of groundwater; however, the health risk assessment of the groundwater revealed no significant carcinogenic risk to the population exposed to it. Hence, the need for water treatment and evaluation of the soil contamination status of landfills.

Chemometric and risk assessment of nitrogen composition of atmospheric rainwater from diverse surfaces in Rivers State, Nigeria.

Organic and inorganic nitrogen ions in the environment play important role across environmental matrices. Rainwater samples collected from ambient and different roofing surfaces (zinc, aluminium, asbestos and stone-coated roofing sheets) from selected locations at Ogale, Rumuodomaya/Rumuodome, Diobu and Chokocho within Rivers State, Niger Delta, Nigeria, from April to June, July to August and September to October depicting three regiments of early, mid and late rains. The samples were analysed for Kjeldahl nitrogen, ammonium, nitrate and nitrite using APHA methodology. Quantitative assessment showed that Kjeldahl nitrogen were in range of 0.11 to 28.05mg/L; ammonium 0.50 to 20.22mg/L, nitrate from 0.12 to 22.69mg/L and nitrite from 0.15 to 3.90mg/L. Parameters decreased from early to late rain, which can be attributed to rain dilution factor potential, wind pattern and emission from anthropogenic sources that influenced the rainwater quality across surfaces. Nitrogen results showed that dry and wet deposition has great impact; atmospheric aerosols and biogeochemical interactions can affect water quality. Monthly variation showed that Ogale had high regression compared to other locations due to close proximity to oil and gas emission and marine contribution. Neutralization factor showed that nitrate-nitrite compounds have strong correlation with ammonium ion. Non-carcinogenic risk assessment using US EPA model showed hazard index less than one (1), thus no associated health effect of nitrate and nitrite in rainwater. In conclusion, it is evident that nitrate/nitrite levels and other nitrogen derivatives in rainwater in crude oil-producing Niger Delta and its continuous consumption can cause negative health outcome.

Assessment of Water Quality Index and Non-Carcinogenic Risk for Ingestion of Nitrate for Drinking Purpose of Bhosga Reservoir, Karnataka, India

Reservoirs are vital water sources that contribute significantly to local ecological and environmental balance, particularly in semi-arid regions. An evaluation of the drinking water quality index (WQI) has been conducted using ten water parameters like electrical conductivity (EC), chloride (Cl-), pH, total hardness (TH), total alkalinity (TA), phosphate (PO43-), dissolved oxygen (DO), nitrate (NO3-), total dissolved solids (TDS), and sulfate (SO42-). Weighed Arithmetic Index technique is utilized for examining drinking water quality status and USEPA model was utilized to determine the non-carcinogenic risk for ingestion of nitrate of Bhosga reservoir of Kalaburagi district which was measured at five predefined sites from October 2020 to September 2021. All the parameters of potable water were below the allowable limits based on given standards. The maximum WQI results were reported in monsoon season, with a mean WQI value of 48.14 from all the five selected sites, with the pre &amp; post-monsoon seasons a mean WQI result of 46.08 and 43.68, respectively. Overall, the WQI value signifies that the water was of good quality, making it worthy for domestic use. The outcome of this study reveals that the pH and DO position have a substantial impact on reservoir WQI. Non-carcinogenic risk for nitrate ingestion reveled that, seasonal HQ average results for adults and children are ranging between 0.036 to 0.040 and 0.065 to 0.071, respectively and the HQ results for both adults and children were below 1, indicating neither adults nor children had any negative effect. Principal component analysis and cluster analysis revealed that primary causes of water quality degradation were agricultural runoff and anthropogenic activities. To ensure the security and the quality of water supply to people who live in the surrounding region, simple filter treating of reservoir water prior usage is needed.

Health Risk Study of Heavy Metals from Consumption of Drugs (Solid and Liquid) Samples Derived from Medicinal Plants in Iraq.

Heavy metals are one of the carcinogenic factors harmful to the safety of human health. In plant-based medications, heavy metals can be found. In February 2022, 28 specimens of medicinal drugs (solid and liquid) were collected from Texas drugstores to investigate heavy metals like zinc, iron, and lead utilizing a Shimadzu AA-7000 atomic absorption spectrophotometer (AAS). The current study used a US EPA model to calculate non-cancer and cancer risk parameters for heavy metals in all medicinal drug specimens. Zinc, iron, and lead levels (mg/kg) in solid samples were 1.95-51.43, 29.09-2055.92, and ND-26.68, respectively, while they were 0.043-4.267, 0.100-5.25, and ND-1.434, respectively, in liquid specimens. The average value of total non-cancer risk (TNCR or HII) and total cancer risk (TCCR) of heavy metals intake in solid specimens was 4.54E - 03 ± 1.1E - 03 and 2.11E - 06 ± 6.0E - 07, while in liquid specimens were 1.98E - 04 ± 4.1E - 05 and 9.44E - 09 ± 2.3E - 09, respectively. Compared to liquid specimens, solid specimens have higher concentrations of heavy metals. The zinc, iron, and lead concentrations in the liquid specimens were lower than the WHO-acceptable standards of 50, 20, and 10mg/kg, respectively. On the other hand, few solid specimen results are more than acceptable. However, all the specimens' TNCR and TCCR results were within the US EPA's globally recommended limits. Finally, the results of the heavy metals show no health hazards associated with using the researched medications.

Health risk assessment of gaseous elemental mercury (GEM) in Mexico City.

Emissions of gaseous elemental mercury (GEM or Hg0) from different sources in urban areas are important subjects for environmental investigations. In this study, atmospheric Hg measurements were conducted to investigate air pollution in the urban environment by carrying out several mobile surveys in Mexico City. This work presents atmospheric concentrations of GEM in terms of diurnal variation trends and comparisons with criteria for pollutant concentrations such as CO, SO2, NO2, PM2.5, and PM10. The concentration of GEM was measured during the pre-rainy period by using a high-resolution active air sampler, the Lumex RA 915 M mercury analyzer. In comparison with those for other cities worldwide, the GEM concentrations were similar or slightly elevated, and they ranged from 0.20 to 30.23 ng m−3. However, the GEM concentration was significantly lower than those in contaminated areas, such as fluorescent lamp factory locations and gold mining zones. The GEM concentrations recorded in Mexico City did not exceed the WHO atmospheric limit of 200 ng m−3. We performed statistical correlation analysis which suggests equivalent sources between Hg and other atmospheric pollutants, mainly NO2 and SO2, emitted from urban combustion and industrial plants. The atmospheric Hg emissions are basically controlled by sunlight radiation, as well as having a direct relationship with meteorological parameters. The area of the city studied herein is characterized by high traffic density, cement production, and municipal solid waste (MSW) treatment, which constantly release GEM into the atmosphere. In this study, we included the simulation with the HYSPLIT dispersion model from three potential areas of GEM release. Emissions from industrial corridors and volcanic plumes localized outside the urban area contribute to the pollution of Mexico City and mainly affect the northern area during specific periods and climate conditions. Using the USEPA model, we assessed the human health risk resulting from exposure to inhaled GEM among residents of Mexico City. The results of the health risk assessment indicated no significant noncarcinogenic risk (hazard quotient (HQ) < 1) or consequent adverse effects for children and adults living in the sampling area over the study period. GEM emissions inventory data is necessary to improve our knowledge about the Hg contribution and effect in urban megacity areas with the objective to develop public safe policy and implementing the Minamata Convention.Supplementary informationThe online version contains supplementary material available at 10.1007/s10661-022-10107-7.

Assessment of the risk of exposure to Air pollutants and identifying the affecting factors on making pollution by PCA, CFA

ABSTRACT Today, one of the most important problems for humans is disease and mortality due to air pollutants, especially in large and industrial cities. This research is to evaluate the health risk of children and adults’ exposure to heavy metals and PAHs in the air of cities of Arak, Isfahan, Ahvaz, Tabriz, Shiraz, Karaj and Mashhad and identifying the factors affecting pollution, based on sampling data from 120 stations, was done during 2019–2020. ICP OES and GC/MS were used to determine the amount of heavy metals and PAHs, respectively. US-EPA models were used for carcinogenic and non-carcinogenic risk assessment and Factor analysis models, PCA, CFA with SPSS and LISREL software were used to identify factors affecting contamination. The risk index for children and adults, except in the cities of Arak and Isfahan, was obtained within the allowable range and the carcinogenicity and non-carcinogenicity risk of all metals, except Mn in Arak and Isfahan for children and adults was seen below the threshold. The carcinogenic risk of all PAHs was also obtained to an acceptable extent. During the statistical analysis, combustion of fuels, vehicle exhaust, tyre wear and industrial activities were identified as the most important factors in causing pollution.

Potential health risk assessment of heavy metal content in Perlis soil

A determination of soil heavy metal (Cu, Mn and Ni) concentrations in Perlis state, Malaysia was performed to define the level of soil pollution. Six soil samples were collected at depth of 0 – 15 cm in industrial, residential and school areas around Perlis. The highest concentration of Mn (57.80 mg/kg) and Ni (2.83 mg/kg) were detected at limestone quarry in Bukit Air, Cu (17.43 mg/kg) in Kampung Wang Ulu. The concentration of Cu, Mn and Ni were well below their soil geochemical background values. The single pollution indices assessment revealed that the soil contamination due to heavy metals in Perlis is insignificant. On the basis of the heavy metal content, the potential health risk assessment for children and adults was calculated for a lifetime of exposure through ingestion, inhalation and dermal contact based on the USEPA model. The exposure assessment found that the exposure pathways of heavy metals to both children and adults are through ingestion. Both Hazard Quotient (HQ) and Hazard Index (HI) values are lower than 1, indicating no health risk. From the result, the HI values indicated that the soil heavy metal contamination could pose more impacts on children as compared to adults.

Comparison of Interpolation Methods for the Mapping of Wind Erosion using the USEPA Model

Comparison of Interpolation Methods for the Mapping of Wind Erosion using the USEPA Model