Heavy metals in brick kiln located area using atomic absorption spectrophotometer: a case study from the city of Peshawar, Pakistan

Toxicological profile and potential health concerns through metals and trace elements exposure in brick kiln workers from Lahore, Pakistan

This study examined levels of lead (Pb), cadmium (Cd), chromium (Cr), copper (Cu), mercury (Hg), and arsenic (As) in blood, hair, and nails of 18 brick kiln workers from three brick kiln units located around a metropolitan city, Lahore, Pakistan. All the trace elements except Hg and As were detected in the studied matrices of Brick kiln workers. In general, brick kiln workers reflect the highest concentration of Pb, followed by Cd, Cr, and Cu. Of the pollutants analyzed, Pb has the highest mean (min-max) concentrations at 0.35 (0.09-0.65) in blood (μg/mL), 0.34 (0.14-0.71) in hairs (μg/g), and 0.44 (0.32-0.59) in nails (μg/g) of brick kiln workers. Following Pb, the trend was Cd 0.17 (0.10-0.24), Cu 0.11(0.03-0.27), and Cr 0.07 (0.04-0.08) in blood (μg/mL), followed by Cr 0.11(0.05-0.20), Cd 0.09 (0.03-0.13), and Cu 0.08 (0.04-0.16) in hairs (μg/g) and Cu 0.16 (0.05-0.36), Cd 0.13 (0.11-0.17), and Cr 0.10 (0.05-0.14) in nails (μg/g) respectively. Relatively higher concentrations of metals and other trace elements in blood depicts recent dietary exposure. The difference of trace elements except Pb was non-significant (P > 0.05) among studied matrices of workers as well as between Zigzag and traditional exhaust-based brick kilns. The concentrations of Pb, Cd and Cr in blood of brick kilns workers are higher than the values reported to cause health problems in human populations. It is concluded that chronic exposure to metals and other trace elements may pose some serious health risks to brick kiln workers which needs to be addressed immediately to avoid future worst-case scenarios.

Influence of chlorine on co-processing of hazardous wastes in brick kilns

Brick kiln co-treatment is a novel industrial hazardous wastes (IHWs) utilization process. However, the effects of chlorine (Cl) in wastes on heavy metals (HMs) during this process are overlooked. This study investigated the stabilization/solidification (S/S) and volatilization, as well as long and short-term leaching, of HMs in Cl-containing bricks. The results indicated enhanced formations of stable mineral phases (NiFe2O4, Ni2SiO4, Cd3Al2Si3O12, CdSiO3, FeCr2O4, Cr2O3, CuFe2O4, and CuAl2O4) in bricks at a low sintering temperature (800 °C) due to the affinity between Cl and HMs. By comparing HM concentrations before and after sintering in bricks, the study observed that Cl's presence significantly elevated the volatilization rates for Cd and Cu by 30.8% and 14.2%, respectively. In contrast, the effect on volatilization for Ni and Cr was not significant. Additionally, utilizing the NEN 7375 method, the cumulative leaching rates of Ni, Cd, Cr, and Cu over a 64-day experiment under extremely acidic conditions were 0.22%, 7.18%, 0.01%, and 1.46%, respectively. Similarly, higher short-term leaching rates of Cd (4.03%) and Cu (5.73%) than those of Ni (0.94%) and Cr (0.08%) were observed. This finding might be attributed to the lower stability of the Cd and Cu solid phases under acidic environments compared to those of Ni and Cr. Surface wash-off, dissolution, and diffusion were the processes governing HM leaching from bricks. The 10-year projections revealed a minimal release of HMs during future extended leaching, implying the successful S/S of HMs. This study provides a reference for assessing the environmental impacts of brick kiln co-processing of Cl-containing IHWs.

Fine particulate matter from brick kilns site and roadside in Lahore, Pakistan: Insight into chemical composition, oxidative potential, and health risk assessment

Background

Human health is seriously threatened by particulate matter (PM) pollution, which is a major environmental problem. A better indicator of biological responses to PM exposure than its mass alone is the PM "oxidative potential (OP)," or ability to oxidize target molecules. When reactive oxygen species (ROS) are generated in the OP in excess of the antioxidant capacity of body due to PM components such metals and organic species, it causes inflammation, deoxyribonucleic acid (DNA), proteins, and lipids damage.

Method

The samples of fine particulate matter (PM2.5) are collected from the brick kiln site and the roadside in Lahore, Pakistan. The organic carbon (OC) and elemental carbon (EC) were estimated by carbon analyzer (DRI 2001A) using the thermal/optical transmittance (TOT) protocol. The water-soluble organic carbon (WSOC) concentration was determined using a total organic carbon analyzer (Shimadzu TOC-L CPN). Ion chromatography (Dionex ICS-900) with a conductivity detector was used to analyze the water-soluble anions (Cl-, NO3-, and SO42-) and cations (NH4+, Na+, K+, Mg2+, and Ca2+). Inductively coupled plasma-mass spectrometry (iCAP TQ ICP-MS, Thermo Scientific) was used to determine the concentrations of metals in the solution. The dithiothreitol (DTT) consumption rate was calculated using a spectrophotometer at a wavelength of 412 nm.

Results

The mean concentrations of PM2.5 at the brick kiln site and roadside reported are 509.3 ± 32.3 μg/m3 and 467.5 ± 24.9 μg/m3, and the average OC/EC ratio is 1.9 ± 0.4 and 2.1 ± 0.1. primary organic carbon (POC) contributed more to OC than secondary organic carbon (SOC), which indicated the dominance of primary combustion sources. The anion equivalent (AE) to cation equivalent (CE) ratio indicated that PM2.5 is acidic at both sites due to the dominance of NO3- and SO42-. The DTT consumption rate normalized by PM2.5 mass (DTTm) and DTT consumption rate normalized by air volume (DTTv) of PM2.5 at the roadside samples are higher than at the brick kiln site due to the higher contribution of ionic species to the mass of PM2.5. Carbonaceous species of PM2.5 at both sampling sites are significantly correlated with DTTv of PM2.5, while metallic species behaved differently. The incremental lifetime cancer risk (ILCR) values (lung cancer) of As and Cr at both sampling sites, while the ILCR value of Cd at the roadside samples is exceeding the permissible limits for adults and children. The lifetime average daily dose (LADD) value for adults is higher than that for children, indicating that children are less vulnerable to metals.

Conclusion

The concentration of PM2.5 at both sampling sites were exceeding the permissible limits of Pakistan' National Environmental Quality Standard (NEQS) and posing risk to the health of the local population. The POC and SOC contribution to OC at the brick kiln site and roadside in Lahore were 84.6%, 15.4% and 84.4%, 15.6%. POC at both sampling sites were the dominant carbon species indicating the dominance of primary combustion sources. The residence of Lahore poses the lung cancer risk due to Cr, As, and Cd at both sampling sites. The results of this study provide important data and evidence for further evaluation of the potential health risks of PM2.5 from brick kiln site and road side in Pakistan and formulation of efficient air-pollution control measures.

Metal pollution in the topsoil of lands adjacent to Sahiwal Coal Fired Power Plant (SCFPP) in Sahiwal, Pakistan

Coal fly ash from a coal fired power plant is a significant anthropogenic source of various heavy metals in surrounding soils. In this study, heavy metal contamination in topsoil around Sahiwal coal fired power plant (SCFPP) was investigated. Within distance of 0-10, 11-20, 21-30 and 31-40 km of SCFPP, total 56 soil samples were taken, 14 replicate from each distance along with a background subsurface soil sample beyond 60 km. Soil samples were subjected to heavy metals analysis including Fe, Cu and Pb by Atomic Absorption Spectrophotometer (AAS). Composite samples for each distance were analyzed for Al, As, Ba, Cd, Co, Cr, Mn, Mo, Ni, Se, Sr, Zn by Inductively Coupled Plasma (ICP). Pollution indices of exposed soil including Enrichment Factor (EF), Contamination Factor (CF), Geoaccumulation Index (Igeo), and Pollution Load Index (PLI) were calculated. Ecological risk index ([Formula: see text]) of individual metals and the Potential Ecological Risk Index (PERI) for all metals were determined. Soil samples within 40 km of SCFPP were significantly polluted with Pb (mean 2.81 ppm), Cu (mean 0.93 ppm), and Fe (mean 7.93 ppm) compared to their background values (Pb 0.45, Cu 0.3, and Fe 4.9 ppm). Some individual replicates were highly contaminated where Pb, Fe, and Cu values were as high as 6.10, 35.4 and 2.51 ppm respectively. PLI, Igeo, CF, and EF for metals classified the soil around CFPP as "moderate to high degree of pollution", "uncontaminated to moderately contaminated", "moderate to very high contamination", and "moderate to significant enrichment" respectively with average values for Cu as 2.75, 0.82, 3.09, 4.01; Pb 4.79, 1.56, 6.16, 7.76, and for Fe as 1.20, 0.40, 1.62, 3.35 respectively. Average Ecological Risk Index ([Formula: see text]) of each metal and Potential Ecological Risk Index (PERI) for all metals classified the soils as "low risk soils" in all distances. However, ([Formula: see text]) of Pb at a number of sites in all distances have shown "moderate risk". The linear correlation of physico-chemical parameter (EC, pH, Saturation %) and metals have recorded several differential correlations, however, their collective impact on Pb in 0-10 km, has recorded statistically significant correlation (p-value 0.01). This mix of correlations indicates complex interplay of many factors influencing metal concentrations at different sampling sites. The concentration of As, Cr, Co, Cd, and Zn was found within satisfactory limits and lower than in many parts of the world. Although the topsoil around SCFPP is largely recorded at low risk, for complete assessment of its ecological health, further research considering comprehensive environmental parameters, all important trace metals and variety of input pathways is suggested.

Toxicological profile and health risk assessment through trace elements exposure in brick kiln workers from Lahore, Pakistan.. [DOI: 10.21203/rs.3.rs-3267981/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

This study examined lead (Pb), cadmium (Cd), chromium (Cr), copper (Cu), mercury (Hg), and arsenic (As) levels in blood, hair, and nails of 18 brick kiln workers from three brick kiln units located around a metropolitan city, Lahore, Pakistan. All the trace elements except Hg and As were detected in the studied matrices of Brick kiln workers. In general, brick kiln workers had the highest concentration of Pb, followed by Cd, Cr, and Cu. Among trace elements, Pb has the highest mean (min-max; µg/g)) concentrations at 0.35 (0.09–0.65) in blood, 0.34 (0.14–0.71) in hairs, and 0.44 (0.32–0.59) in nails of brick kiln workers. Following Pb, the trend was Cd 0.17 (0.10–0.24), Cu 0.11(0.03–0.27), and Cr 0.07 (0.04–0.08) in blood, followed by Cr 0.11(0.05–0.20), Cd 0.09 (0.03–0.13), and Cu 0.08 (0.04–0.16) in hairs and Cu 0.16 (0.05–0.36), Cd 0.13 (0.11–0.17), and Cr 0.10 (0.05–0.14) in nails respectively. The difference of trace metals except Pb was non-significant (P > 0.05) among studied matrices of workers as well as between Zigzag and traditional exhaust based brick kilns. Non-carcinogenic risk of Pb and Cd were above USEPA and WHO limits while Pb, Cd, and Cr carcinogenic risks were close to the threshold limits. It is concluded that chronic exposure to trace elements poses serious health risks to brick kiln workers which needs to be addressed to avoid future worst-case scenarios.

Assessment and mapping of total suspended particulate and soil quality around brick kilns and occupational health issues among brick kilns workers in Pakistan

Brick kilns constitute one of the major sources of environmental degradation in Pakistan. The present study was conducted to determine the soil quality and total suspended particulates (TSPs) around the brick kilns and assess the health effects on brick kiln workers. Four brick kilns were selected, two each at Sheikhupura and Pattoki city. The soil quality was assessed by analyzing pH, electrical conductivity, moisture content, nitrogen, phosphorus, potassium content, and heavy metal concentration while TSPs were measured by hand-held Microdust Pro Real time monitor. Average TSP concentration around brick kilns at Sheikhupura and Pattoki ranged between 1100 and 1200 µg/m³ and between 550 and 600 µg/m³ respectively which exceeded the Punjab Ambient Air Standards. The soil was slightly acidic (Sheikhupura: average pH = 6.41; Pattoki: average pH = 6.6) while all other analyzed parameters, except heavy metals, were lower than the required FAO Standards for good quality agriculture soil. Heavy metal accumulation in soil samples followed the general order zinc (Zn) > chromium (Cr) > nickel (Ni) > manganese (Mn) > cadmium (Cd) > copper (Cu). For assessment of occupational health and safety issues, all 440 brick kiln workers from the study areas were interviewed. Mostly, brick kiln workers suffered from chronic back pain (84%), skin issues (80.5%), dry cough (72.9%), common cold (46.1%), and shortness of breath (17.1%). The vulnerability risk varied with the nature of the work as workers engaged in brick baking were more vulnerable to respiratory issues than were those in molding task. The study concludes that brick kilns are a source of increased TSP, deteriorated surrounding soil quality, and impaired worker health. It is necessary to regulate these activities and implement requisite health and safety measures.

Heavy metal load and effects on biochemical properties in urban soils of a medium-sized city, Ancona, Italy

Urban soils are often mixed with extraneous materials and show a high spatial variability that determine great differences from their agricultural or natural counterparts. The soils of 18 localities of a medium-sized city (Ancona, Italy) were analysed for their main physicochemical and biological properties, and for chromium (Cr), copper (Cu), cobalt (Co), lead (Pb), nickel (Ni), zinc (Zn), and mercury (Hg) total content, distribution among particle-size fractions, and extractability. Because of the absence of thresholds defining a hot spot for heavy metal pollution in urban soils, we defined a "threshold of attention" (ToA) for each heavy metal aiming to bring out hot spot soils where it is more impellent to intervene to mitigate or avoid potential environmental concerns. In several city locations, the soil displayed sub-alkaline pH, large contents of clay-size particles, and higher TOC, total N, and available P with respect to the surrounding rural areas, joined with high contents of total heavy metals, but low availability. The C biomass, basal respiration, qCO₂, and enzyme activities were compared to that detected in the near rural soils, and results suggested that heavy metals content has not substantially compromised the soil ecological services. We conclude that ToA can be considered as a valuable tool to highlight soil hot spots especially for cities with a long material history and, for a proper risk assessment in urban soils, we suggest considering the content of available heavy metals (rather than the total content) and soil functions.

Assessment and Impacts of Air Pollution from Brick Kilns on Public Health in Northern Pakistan

Brick kilns add enormous quantities of organic pollutants to the air that can cause serious health issues, especially in developing countries; poor air quality is associated with community health problems, yet receives no attention in Northern Pakistan. The present study, therefore, assessed the chemical composition and investigated the impacts of air pollution from brick kilns on public health. A field-based investigation of air pollutants, i.e., PM1, PM2.5 and PM10, CO2, CO, NO, NO2, H2S, and NH3 using mobile scientific instruments was conducted in selected study area locations. Social surveys were conducted to investigate the impacts of air pollution on community health. The results reveal the highest concentrations of PM1, PM2.5, and PM10, i.e., 3377, 2305, and 3567.67 µg/m3, respectively, in specific locations. Particulate matter concentrations in sampling points exceeded the permissible limits of the Pakistan National Environmental Quality Standard and, therefore, may risk the local population’s health. The highest mean value of CO2 was 529 mg/L, and other parameters, such as CO, NO, NO2, H2S, and NH3 were within the normal range. The social survey’s findings reveal that particulate matter was directly associated with respiratory diseases such as asthma, which was reported in all age groups selected for sampling. The study concluded by implementing air pollution reduction measures in brick kiln industries to protect the environment and community health. In addition, the region’s environmental protection agency needs to play an active role in proper checking and integrated management to improve air quality and protect the community from air hazards.

Apportionment of heavy metals in a soil-water-plant system via brick kiln emissions in heavily industrialized city of Pakistan

One of the major environmental problems is the fast accumulation of brick kiln emissions near the peripheries of almost all urban centers. An enormous quantity of substandard coal, wood, rubber tires, or saw wood is used as fuel in these brick kilns, creating environmental pollution through carbon and heavy metals present in the emissions. The present study was designed to determine the distribution pattern of heavy metals in a soil-water-plant system under the influence of brick kiln emissions. Ash, soil (0-15 cm), water, and plant samples were collected from the adjacent areas of the brick kilns. Geo-accumulation index and contamination factors were used to assess the toxicity of metals to soil and plants. It was found that the concentrations of Cd in water, soil, coal, and plant samples were found in the range of 0.004-0.024 mg L^-1, 0.02-0.66, 0.002-0.042, and 0.06 to 0.07 mg kg^-1, respectively, while Pb concentration was found within the range of 0-0.08 mg L^-1, 0.30-8.60, 0.011-0, and 0.01-0.08 mg kg^-1 in water, soil, and plant samples, respectively. The concentration of Cd in brick kilns ash was in the range of 0-0.04 mg kg^-1 while Pb was found within the range of 0.01-0.05 mg kg^-1 for ash. Geo-accumulation index and contamination factor values for Cd were found higher suggesting proper pollution prevention measures to be implemented. Based on the results, it was concluded that Cd concentrations in soil, plants, and water samples were higher in the subject area due to brick kiln emissions and higher Cd concentrations in the fuel material.

Study of impacts of brickkiln emanations on soil quality of agriculture lands in selected areas of District Bhimber, Azad Jammu and Kashmir, Pakistan

The pollution is hot issue of current era in world and the current study was carried to explore impacts of brickkilns' emanations on physiochemical properties of agricultural lands from District Bhimber of Azad Jammu and Kashmir (AJK) Pakistan. In this research, various edaphic characteristics: pH, soil organic matter, organic carbon, water holding capacity, cation exchange capacity and heavy metal contamination in soils nearby of brickkilns were determined. The pH of soil ranged from 5.55 to 7.50, soil organic matter was 0.35-0.90% and organic carbon content was 0.65-1.40%. The water holding capacity ranged from 2.10 to 3.20 mgL-1 and carbon exchange capacity was 1250 to 4202 meq/100g. The contamination profile of heavy metal depicted that Pb showed highest conc. 0.065 mg/g followed by Co (0.053 mg/g) and Ni with 0.52 mg/g in the soil. Pb and Cr had high conc. in soil samples around brickkilns due to burning of coal and rubber tyres as fuel. The conc. of sulphate and nitrate ranged from 0.90±0.50 mol L-1 to 4.25±0.65 mol L-1 and 2.30±0.50 mol L-1 to 6.55±0.25 mol L-1, respectively. The fertility of agriculture lands was depicted that edaphic properties were directly related while nutritive features were inversely commensurate to distance from brickkilns. The research proved that emanations of brickkilns causes severe impact on quality of agriculture land, plant growth and its yield. Hence, reclamation measures should be taken to mitigate and/or eradicate nuisance of brickkilns emanations by using environmental friendly strategies.

A scoping review of sources of mercury and its health effects among Pakistan's most vulnerable population

Mercury and methyl mercury are poisonous to human body. In the recent times, exposure to mercury has been anthropogenic in nature. Within the past several decades, many incidences of mercury poisoning have been documented in several countries including Pakistan. Mercury has been ingested where it has been used to preserve crops, through the point and non-point source discharge into the surface water, and consequently entering the food chain. We conducted this scoping review of mercury and its health effects in Pakistan in order to raise the flag to a silent ongoing Minamata disease in the country. We conducted a systematic search of the available literature in Google Scholar, PubMed, and grey literature of unpublished theses and reports of various universities across the country. We found that in the northern Pakistan, suspended sediments were the major pathway of the riverine mercury transport. Sediments of Hunza and Gilgit River were found high in mercury concentrations. Gold mining leads to an increase in mercury concentration in soil and river waters flowing in this region. High concentrations up to 108 ng/L were found in Shimsal River. It is suspected that that high level of mercury transport may be leading to accumulation of mercury in major water bodies and lakes downstream. Occupational exposure to mercury and other heavy metals is common in an unregulated private sector of the country. Goldsmiths burn the amalgamated gold without personal protective measures. Direct exposure to the fumes of mercury leads to respiratory, dermatological, systemic and neurological ailments specific to mercury poisoning. We found good evidence of bioaccumulation of mercury in fish and fish products in Pakistan. The untreated waste water discharge is responsible to not only afflicted the fish but also the birds which feed on this fish. Further, the same untreated waste water from factories and agriculture runoffs affect vegetables grown in it. Studies looking at the biomarkers for mercury in humans have shown increased and even toxic levels of mercury among the most vulnerable populations of the country. Other sources of mercury exposure included mercury in traditional medicines and cigarette products. Though no evidence was found for its presence in drinking water, its existence in the food chain and occupational exposure pose great threat to the humans as well as animals.

Evaluation of environmental effects of heavy metals on biochemical profile and oxidative stress among children at brick kiln sites

The present study was designed to study the health risks among children living at brick kiln industries. A survey was conducted, questionnaires were filled out, and demographic data was collected from Punjab, Pakistan. Heavy metals burden and BMI were calculated, hematological and enzyme analysis, comet assay and hormonal ELISA were performed. The results showed decreased BMI, RBC count and hematocrit in the exposed group. Nickel, cadmium, zinc and chromium concentrations in whole blood were detected among exposed children. Antioxidant enzymes and growth hormone concentration decreased, while reactive oxygen species and cortisol level increased in the exposed group. The comet assay findings showed decreased percentage DNA in the head and increased in the tail region among exposed group. It was concluded that children living at brick kiln sites experienced decreased BMI, altered antioxidant enzymes status and hormone levels and cellular DNA damage that pose a major threat on child health.

Adsorption and sugarcane-bagasse-derived activated carbon-based mitigation of 1-[2-(2-chloroethoxy)phenyl]sulfonyl-3-(4-methoxy-6-methyl-1,3,5-triazin-2-yl) urea-contaminated soils

Burgeoning pesticide usage in agriculture sector required to be evaluated by assessing the adsorption rate in soils. The herbicide triasulfuron was used in this research to analyze its sorption behavior in seven distinct soils using batch equilibrium methodology. The adsorption coefficient (Kd) values ranged from the 3.32 to 29.7 µg/mL. Peshawar soil displayed the highest Kd value because of the distinct physiochemical properties when compared with the other six samples. Gibbs free energy exhibited negative values displaying less contact between soil particles and pesticides, showing the exothermic nature of the phenomena. A negative association was observed between the pH of the soil samples and Kd (R2 = −0.71) but a direct relation with the organic content (R2 = 0.74). Triasulfuron mitigation was performed by the economical remediation of soils using acid-activated charcoal prepped from Saccharum officinarum husk. Activated carbon derived from biomass displayed the great potential for triasulfuron removal from soils.

Study of occupational exposure to brick kiln emissions on heavy metal burden, biochemical profile, cortisol level and reproductive health risks among female workers at Rawat, Pakistan

The present study was planned to understand the heavy metal burden and its possible actions in blood of occupational females working at brick kilns at Rawat, Pakistan. A total of 232 women were included in the study, of which 114 presented control subjects. Apart from collection of demographic data, fertility indicators and body mass index (BMI), blood was collected from subjects that was later used for the determination of heavy metal concentrations using atomic absorption spectroscopy and haematological profile. Blood was centrifuged and plasma was obtained and stored at - 20° to study biochemical variables (sodium dismutase, peroxidase, reactive oxygen species, thiobarbituric acid reactive species, protein estimation), lipid profile and cortisol concentrations among the two groups. Analysis of heavy metal in blood showed elevated levels of cadmium (3.09 ± 0.01 μg/dl), chromium (4.20 ± 0.02 μg/dl) and nickel (5.59 ± 0.03 μg/dl) in worker's group as compared with control. Increased platelet count; decreased antioxidant enzyme and increased oxidants level; increased total cholesterol, low-density lipoprotein (LDL) and triglyceride (TG); decreased total protein and high-density lipoprotein (HDL); and increased cortisol levels were evident among workers as compared with the control group. The study concluded that occupational workers experience increased heavy metals burden in blood and, therefore, pose a risk to human health by causing reduction in antioxidant enzymes concentration and increase in stress conditions.

Multilayer arsenic mobilization and multimetal co-enrichment in the alluvium (Brahmaputra) plains of India: A tale of redox domination along the depth

The study attempts to understand arsenic (As) mobilization in a shallow aquifer with depth variation while focusing on the potential co-occurrence of As with priority metals (zinc and lead), using a pilot scale multilevel groundwater monitoring system (MGWS). Groundwater samples (n = 72) were collected bi-weekly (every 15 days) from the multilevel sampler (4.6, 9.2 and 13.8 m depths), installed at Tezpur, Sonitpur district of Brahmaputra floodplain (BFP), Assam, India, for a period of 1 year (August 2013-July 2014). Both geogenic and anthropogenic influences were found to affect the studied unconfined aquifer. At 4.6 m, weathering dominated due to interaction with CO₂ and infiltrating water. Prevalent high pH (7.9-8.6) at all three depths in association with strong oxidizing condition (at 4.6 m) during the drier months seem to play a crucial role in desorption based As release. Multivariate analyses revealed that redox potential (ORP) remains the primary controller of As release at all three depths. With depth, stronger anoxic conditions resulted in the dominance of reductive hydrolysis leading to a co-occurrence scenario of As (max 4.6 μgL^-1) with Zn (max 2514 μgL^-1) and Pb (max 740 μL^-1) with influences of anthropogenic modes of activities like agriculture and dry deposition from a brick kiln. Multi-element enrichment is an emerging concern but the bigger picture would be to understand the peculiarities of individual aquifers, as a generalization can lead to missing a ton of information. In this regard, long-term multilevel monitoring can help in the predictive understanding of the vertical stratification and co-occurrences of multi-metals that can subsequently be applied for water production at the safer depths.

Redox balance and DNA fragmentation in arsenic-exposed occupational workers from different industries of Pakistan

AbstractOccupational exposure accounts for a contact between workers and different toxicants. Present study was designed to measure the arsenic-induced DNA fragmentation and oxidative stress in exposed workers. Blood, hair, and nail samples were collected from welding, brick kiln, furniture, pesticide, and paint industries (n = 50/industry) of Pakistan along with 200 controls. DNA damage was calculated using DNA fragmentation assay. Antioxidant enzymes (CAT, SOD, GPx) were measured using ELISA. Results revealed that arsenic exposure induced DNA fragmentation in brick kiln, furniture, and welding industries. Enzyme activity was reduced in five industries compared to control. In exposed group, significant depletion of enzymes was observed in furniture, welding, and brick kiln workers. Based on age and time of exposure, significant difference was observed in welding and brick kiln group. Smokers of exposed group showed significantly reduced levels of enzymes compared to controls. Arsenic deposition was observed higher in the hair, nail, and blood samples of exposed group (P < 0.001) compared to control. Likewise, lead and cadmium contents were higher in the blood samples of industrial workers compared to control. This study suggests increased trend of cellular damage and oxidative stress in occupational workers profoundly in welding, furniture, and brick kiln industries. Moreover, this study recognizes the contribution of age, exposure time, and smoking status toward arsenic-induced oxidative stress and DNA fragmentation.

Antioxidant enzymes status and reproductive health of adult male workers exposed to brick kiln pollutants in Pakistan

The present study was designed to study the effect of brick kilns emissions on the reproductive health and biochemical status of brick kiln workers and people living in the area near brick kilns. Body mass index (BMI) was significantly reduced in brick makers, carriers, and bakers compared to the control. Red blood cells count and hematocrit (%) were significantly high in brick bakers while MCH was significantly reduced in brick makers and brick bakers. Heavy metals (lead, cadmium, and chromium) concentration in whole blood of the brick kiln workers were significantly higher as compared to the control. Antioxidant enzymes (CAT, SOD, POD, GSH, and GR) were significantly reduced in brick kiln workers as compared to the control while TBARS level were significantly high in brick bakers as compared to the control. Plasma leutinizing hormone (LH) was significantly high in brick bakers while testosterone concentrations were significantly reduced in brick makers, carriers, and bakers. The present study shows that brick kiln workers and people living in the brick kiln vicinity are exposed to heavy metals and other pollutants that is a serious threat to their health. Alternate technology is needed to be developed and brick kilns should be replaced.

Gaseous pollutants from brick kiln industry decreased the growth, photosynthesis, and yield of wheat (Triticum aestivum L.)

Gaseous pollutant emissions from brick kiln industries deteriorate the current state of ambient air quality in Pakistan and worldwide. These gaseous pollutants affect the health of plants and may decrease plant growth and yield. A field experiment that was conducted to monitor the concentration of gaseous pollutants emitted mainly from brick kilns in the ambient air and associated impacts on the growth and physiological attributes of the two wheat (Triticum spp.) cultivars. Plants were grown at three sites, including control (Ayub Agriculture Research Institute, AARI), low pollution (LP) site (Small Estate Industry), and high pollution (HP) site (Sidar Bypass), of Faisalabad, Pakistan. Monitoring of ambient air pollution at experimental sites was carried out using the state-of-art ambient air analyzers. Plants were harvested after 120 days of germination and were analyzed for different growth attributes. Results showed that the hourly average concentration of gaseous air pollutants CO, NO2, SO2, and PM10 at HP site were significantly higher than the LP and control sites. Similarly, gaseous pollutants decreased plant height, straw and grain yield, photosynthesis and increased physical injury, and metal concentrations in the grains. However, wheat response toward gaseous pollutants did not differ between cultivars (Galaxy and 8173) studied. Overall, the results indicated that brick kiln emissions could reduce the performance of wheat grown in the soils around kilns and confirm the adverse impacts of pollutants on the growth, yield, and quality of the wheat.

Metal exposure in schoolchildren and working children. A urinary biomonitoring study from Lahore, Pakistan

In order to document the exposure to trace metals among urban schoolchildren and rural working children, we measured the urinary concentrations of metals in schoolchildren from two areas of differing traffic intensity in Lahore, and in children working in carpet weaving or the brick industry outside Lahore. In a cross-sectional design, we recruited a convenience sample of 339 children aged 8-12 years (mean age 9.9 y, SD 1.4; 47% girls) from two elementary schools in Lahore - one situated in a high air pollution area (n=100) and one situated in an area with lower air pollution (n=79) - and from the carpet weaving industry (n=80) and brick industry (n=80). A spot urine sample was collected and concentrations of 20 metals and metalloids were measured by inductively coupled plasma-mass spectrometry (ICP-MS). Samples of drinking water were similarly analyzed. In general, the urinary concentrations of several toxic metals (including Cr, Mn, As, Mo, Cd, Pb, U) were higher than international reference values. Concentrations of As were especially elevated in children working in the brick making industry [geometric mean (GM) 118 μg/L], but they were also high among urban schoolchildren (GM 68 μg/L and 56 μg/L). Lead (Pb) was higher in urine from schoolchildren in the high air pollution area (GM 11 μg/L) than in those from the lower pollution area (GM 5.3 μg/L). Uranium (U) was high in both carpet weavers (GM 0.28 μg/L) and brick kiln workers (GM 0.45 μg/L). Concentrations of As, Pb, and U in drinking water corresponded well with urinary concentrations of metals. This descriptive study provides evidence for a high exposure to several toxic metals in this area of Pakistan. The concentrations of urinary As are in the order of those found in other regions of the world with high environmental exposure to As. The sources and pathways of exposure and the health significance of these findings need to be further investigated.

Pulmonary dysfunctions, oxidative stress and DNA damage in brick kiln workers

Brick kilns in the suburban areas in developing countries pose a big threat to the environment and hence the health of their workers and people residing around them. The present study was planned to assess the lung functions, oxidative stress parameters and DNA damage in brick kiln workers. A total of 31 male subjects working in brick kiln, and 32 age, sex and socioeconomic status matched controls were included in the study. The lung volumes, capacities and flow rates, namely, forced expiratory volume in first second (FEV1), forced vital capacity (FVC), FEV1/FVC, expiratory reserve volume, inspiratory capacity (IC), maximal expiratory flow when 50% of FVC is remaining to be expired, maximum voluntary ventilation, peak expiratory flow rate and vital capacity were significantly decreased in the brick kiln workers. Increased oxidative stress as evidenced by increased malonedialdehyde levels and reduced glutathione content, glutathione S-transferase activity and ferric reducing ability of plasma were observed in the study group when compared with controls. Our results indicate a significant correlation between oxidative stress parameters and pulmonary dysfunction, which may be due to silica-induced oxidative stress and resulting lung damage.

In vitro assessment of iron effect on porcine ovarian granulosa cells: secretory activity, markers of proliferation and apoptosis

It would be desirable to expand the existing general knowledge concerning direct action of metals on the ovary. Nevertheless, the results of testing of iron compound on porcine ovarian cells should be interpreted carefully because iron is an essential element which could also induce changes in cellular processes. The aim of this in vitro study was 1) to examine dose-dependent effects of iron on the secretory activity of porcine ovarian granulosa cells, and 2) to outline the potential intracellular mediators mediating these effects. Specifically, we evaluated the effect of iron sulphate on the release of insulin-like growth factor I (IGF-I) and progesterone, as well as the expression of markers of proliferation (cyclin B1) and apoptosis (caspase-3) in porcine ovarian granulosa cells. Concentrations of IGF-I and progesterone were determined by RIA, cyclin B1 and caspase-3 expression by immunocytochemistry (ICC). Our results show a significantly decreased IGF-I secretion by ovarian granulosa cells after iron sulphate addition at the doses 0.5 and 1.0 mg/ml. The iron sulphate additions at doses 0.17 and 1.0 mg/ml had no effect on progesterone secretion. In contrast, iron sulphate addition at doses 0.17-1.0 mg/ml resulted in stimulation of cyclin B1 and caspase-3 expression. In conclusion, the present results indicate a direct effect of iron on 1) secretion of growth factor IGF-I but not steroid hormone progesterone, 2) expression of markers of proliferation (cyclin B1), or 3) apoptosis (caspase-3) of porcine ovarian granulosa cells. These results support an idea that iron could play a regulatory role in porcine ovarian function: hormone release, proliferation and apoptosis.

In vitro assessment of molybdenum-induced secretory activity, proliferation and apoptosis of porcine ovarian granulosa cells

Molybdenum (Mo) is an essential trace element and it plays an important role in cell functions. The mechanism of the action of molybdenum in connection with growth factor IGF-I, proliferation-related peptide cyclin B1 and apoptosis-related peptide caspase-3 has not been examined previously in porcine ovarian granulosa cells. The general objective of this in vitro study was to examine the secretory activity of porcine ovarian granulosa cells after experimental Mo administration and to outline the potential intracellular mediators of its effects. Ovarian granulosa cells were incubated with ammonium molybdate for 18 hours: 1.0 mg/mL; 0.5 mg/mL; 0.33 mg/mL; 0.17 mg/mL and 0.09 mg/mL, while the control group received no Mo. The secretion of IGF-I was assessed by RIA and expression of cyclin B1 and caspase-3 by immunocytochemistry. IGF-I release was decreased by Mo addition at the doses 1.0 mg/mL and 0.5 mg/mL. The expression of cyclin B1 was stimulated by Mo addition at all doses ranging from 1.0-0.09 mg/mL. Caspase-3 expression was also stimulated after experimental Mo addition at the doses 1.0 and 0.5 mg/mL. These data contribute to new insights regarding the mechanism of action of Mo on porcine ovarian functions, secretory activity, proliferation and apoptosis of granulosa cells through hormonal and intracellular substances such as are cyclin B1 and caspase-3.