Assessment of cause-specific mortality and disability-adjusted life years (DALYs) induced by exposure to inorganic arsenic through drinking water and foodstuffs in Iran

Assessment of health risk and burden of disease associated with dietary exposure to pesticide residues through foodstuffs in Iran

The health risk and burden of disease associated with dietary exposure to pesticide residues in foodstuffs in Iran were assessed. The pesticide residue levels in foodstuffs in the country were determined through systematic review and meta-analysis. The non-carcinogenic risk, carcinogenic risk, and attributable burden of disease were estimated in terms of hazard quotient (HQ), incremental lifetime cancer risk (ILCR), and disability-adjusted life year (DALY), respectively. The meta-analysis showed that 58% of pesticide-food pairs lacked Codex maximum residue levels (MRLs), 34% had pesticide levels below these limits, and 8% exceeded them. Based on the average HQs, two foodstuffs (onion and tangerine) and two pesticides (haloxyfop-R-methyl and cyhalothrin) exhibited unacceptable non-cancer risk (>1.0). The average ILCR value of lindane was assessed to be at the unacceptable level (1.4 × 10-4). The total annual disease burden values attributable to pesticide residues in foodstuffs were assessed to be 242 for death cases, 0.29 for death rate (per 100,000 people), 13,792 for DALYs, and 16.1 for DALY rate. The three food items with the highest DALY rates from pesticide residues were cucumber (5.9), fish (3.9), and date (2.1). The health risk and disease burden of pesticide residues in foodstuffs were considered to be relatively high.

Arsenic toxicity exacerbates China's groundwater and health crisis

Arsenic (As) contamination is considered a major threat to groundwater quality and human health. The uneven distribution of arsenic contributes to regional variations, creating discrimination related to arsenic enrichment and carcinogenic risk. Here, we have analyzed 2,737 groundwater samples across China, which spans a broad range of geo-environments, climates and land use types. We find that regional inequality of groundwater arsenic concentration is caused by ontology environment. By mapping the groundwater arsenic distribution across China and conducting a global meta-analysis, the spatial response of arsenic concentration to different cancer risks was revealed, and neglected As(V) should be given attention. A random forest analysis identified chemical properties (including oxidation-reduction potential, pH, total manganese ion, total iron ion, total dissolved solids, and sulfate ion) as the most influential drivers, contributing 56% to the model's explanatory power, followed by geographical factors at 28%, climatic factors at 10%, and human activities at 6%. Additionally, reducing the proportion of groundwater supply with high arsenic concentration in drinking water in regions without water treatment may help lower the potential carcinogenic risk. This study emphasizes the potential health risk associated with high arsenic groundwater, making it particularly important to roll out efficient water purification technologies given the natural enrichment of arsenic, especially rural regions.

Assessing human toxicity and ecotoxicity impacts of agricultural pesticide use in Iran based on the USEtox model

The human health and ecotoxicity impacts of agricultural pesticide use in Iran in 2022 were estimated. The impacts of agricultural pesticide use in Iran by pesticide, crop, and province were assessed based on the USEtox model in terms of disability-adjusted life year (DALY) for human health and potentially disappeared fraction of freshwater ecosystem species (PDF) for ecotoxicity. The annual mass of agricultural pesticide use in Iran in 2022 was 17,188 tons, consisting of herbicides (46.2 %), insecticides (30.0 %), and fungicides (23.8 %). The DALYs and DALY rate (per 100,000 people) of agricultural pesticide use in Iran were determined to be 25,140 and 29.4, respectively. The ecotoxicity impact of agricultural pesticide use in Iran was calculated to be 3.35 × 10+12 PDF m3 d. Over 79 % of the human health and ecotoxicity impacts of agricultural pesticide use were attributed to six pesticides (chlorpyrifos, deltamethrin, ethion, phosalone, thiodicarb, and abamectin) and eight crops (pistachio, apple, fig, vegetables, date, orange, wheat and barley, and cotton). While the contributions of the pesticides to the human health and ecotoxicity impact were not the same, chlorpyrifos ranked highest in both human health (28.8 %) and ecotoxicity (49.9 %) impacts. The highest provincial human health and ecotoxicity impacts of agricultural pesticide use were observed in Tehran (4,201 DALYs) and Fars (3.66 ×10+11 PDF m3 d), respectively. The provincial human health and ecotoxicity impacts were mainly driven by population and cropland area, respectively. Given the considerable human health and ecotoxicity impacts, developing national and provincial action plans for more sustainable use of pesticides in Iran is strongly recommended.

The burden of cancer attributable to dietary dioxins and dioxin-like compounds exposure in China, 2000-2020

Dioxin is a typical class of persistent organic pollutants (POPs) that could cause cancer. In China, the contribution of dietary dioxins to the cancer burden remains underexplored. This study evaluates the cancer risk and burden due to dietary dioxins and dioxin-like compounds among Chinese residents from 2000 to 2020. Based on adjustments in China's dioxin policies, the study period was divided into three stages with split years of 2007 and 2014 to estimate the toxic equivalent (TEQ) of dioxins. Participants in dietary surveys conducted in 31 provinces were included. Dietary exposure to dioxins was estimated in a probability model and compared with the provisional tolerable monthly intake (PTMI). The risk was assessed using carcinogenic slope factors and expressed as the incremental lifetime cancer risk (ILCR). A two-stage model evaluated the burden of cancer attributable to dietary dioxins and dioxin-like compounds. Among all food categories, the highest concentration of dioxins and dioxin-like compounds was observed in aquatic foods at 0.15 pg TEQ/kg. Median dietary exposure to dioxins among Chinese residents decreased from 12.39 pg TEQ/kg/month to 8.72 pg TEQ/kg/month between 2000 and 2020. Consequently, the ILCR due to dietary dioxins declined from 6.44 × 10-5 to 4.53 × 10-5. The health risks were higher in younger groups and among residents of coastal areas (P < 0.001). The burden of cancer attributable to dietary intake of dioxins and dioxin-like compounds in the Chinese population in 2000-2007, 2008-2014, and 2015-2020 was 2.25 (2.09-2.42) per 100,000, 2.20 (2.06-2.35) per 100,000, and 1.68 (1.60-1.77) per 100,000, respectively. Furthermore, the disease burden was highest for prostate cancer in men and for breast cancer in women. The dioxin management policies has reduced the burden of cancer attributable to dietary exposure to dioxins and dioxin-like compounds in China. However, excess exposure in coastal areas and children remains a priority for attention.

New insights into mechanism of ellagic acid alleviating arsenic-induced oxidative stress through MAPK/keap1-Nrf2 signaling pathway response, molecular docking and metabolomics analysis in HepG2 cells

The increase of oxidative stress level is one of the vital mechanisms of liver toxicity induced by arsenic (As). Ellagic acid (EA) is widely known due to its excellent antioxidation. Nevertheless, whether EA could alleviate As-induced oxidative stress and the underlying mechanisms remain unknown. Herein, As (2 and 4 μM) and EA (25 and 50 μM) were selected for alone and combined exposure of HepG2 cells to investigate the effects of EA on As-induced oxidative stress. Results indicated that EA could alleviate the oxidative stress caused by As via decreasing intracellular ROS level and MDA content, as well as improving SOD, CAT and GSH-PX activities. qRT-PCR showed that EA might enhance the expression levels of antioxidant enzymes NQO1, CAT and GPX1 by activating MAPK (JNK, p38 and ERK)/keap1-Nrf2 signaling pathway. EA was found to promote dissociation from keap1 and nuclear translocation of Nrf2 by competing with Nrf2 at ARG-380 and ARG-415 sites on keap1 to exert antioxidation using molecular docking. Moreover, metabolomics revealed that EA might maintain the redox balance of HepG2 cells by modulating or reversing disorders of carbon, amino acid, lipid and other metabolisms caused by As. This study provides diversified new insights for the removal of liver toxicity of As and the application of EA.

Analysis of trace elements in processed products of grapes and potential health risk assessment

Raisins and grape pekmez are consumed commonly by human all over the globe. Consumption of contaminated foods may be the likely pathway of heavy metal exposure. Therefore, the objectives of the present research were to quantify trace elements concentration in raisins and grape pekmez produced from locally grown grapes in Gonabad and to assess non-carcinogenic (HQ and HI) and carcinogenic (total cancer risk, CRt) health risks caused by trace elements exposure via oral intake of these products for children, teenagers, and adults. For this purpose, a totally 30 (15 raisins and 15 grape pekmez) samples were purchased from the vineyard gardeners and examined for ten trace elements including As, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, and Zn. The HI values signaled that the studied population consuming these products is at risk. The HQ, HI, and CRt values of the elements were in order of children > teenagers > adults. The highest cancer risk contribution was attributed to As and Ni for all the studied age groups in both raisins and grape pekmez samples. However, it is recommended that the concentration of trace elements in the soil and crops of the study area and its related health risks be regularly monitored to avoid significant health risks in the future.

Nanoporous gold microelectrode for electrochemical sensing of As(III) in cellular environment

The highly toxic arsenite (As(III)) could cause serious cytotoxicity on metabolism, resulting in several diseases. However, it is still a great challenge on the precise sensing of As(III) in complicated conditions, especially in cellular environment. In this work, a nanoporous gold microelectrode (NPG-μE) was fabricated by a simple electrochemical alloying/dealloying method and developed for the electroanalysis of As(III) in the lung cancer cellular (A549 cells) environment. The as-fabricated NPG-μE exhibited the excellent electrochemical performance towards As(III) detection at physiological pH (0.1 M PBS solution, pH 7.4) with a high sensitivity of 5.07 μA ppb-1 cm-2 and a low limit of detection of 0.25 ppb (S/N = 3). The large surface area derived from the nanoporous structure, and the well-dispersed active sites as well as the highly electro-catalytic activity of gold played a critical role on the improved electrochemical behaviors. Furthermore, the effect of the exposure time on electrochemical monitoring As(III) in A549 cellular environment was successfully investigated, revealing the fatal impact of As(III) on cell cycle. This work offered a great trial on investigating of the cytotoxicity of arsenite and their precise detection in complicated cellular environment.

Prediction of human health risk and disability-adjusted life years induced by heavy metals exposure through drinking water in Fars Province, Iran

Exposure to heavy metals in contaminated drinking water is strongly correlated with various cancers, highlighting the burden of disease. This study aimed to assess the non-carcinogenic and carcinogenic risks associated with exposure to heavy metals (As, Pb, Cd, and Cr) in drinking water of Fars province and evaluate the attributed burden of disease. Non-carcinogenic risk assessment was performed using the hazard quotient (HQ) method, while the carcinogenic risk assessment utilized the excess lifetime cancer risk approach. The burden of disease was evaluated in terms of years of life lost, years lived with disability, and disability-adjusted life years (DALY) for three specific cancers: skin, lung, and kidney cancer. The average drinking water concentrations of arsenic (As), cadmium (Cd), chromium (Cr) and lead (Pb) were determined to be 0.72, 0.4, 1.10 and 0.72 μg/L, respectively. The total average HQ of heavy metals in drinking water in the study area were 0.127, 0.0047, 0.0009 and 0.0069, respectively. The average ILCRs of heavy metal in the entire country were in the following order: 1.15 × 10-5 for As, 2.22 × 10-7 for Cd and 3.41 × 10-7 for Cr. The results also indicated that among the various counties analyzed, Fasa experiences the greatest burden of disease in terms of DALYs, with a value of 87.56, specifically attributed to cancers caused by exposure to arsenic. Generally, it can be said that the burden of disease is a critical aspect of public health that requires comprehensive understanding and effective intervention.

Evaluation of Drinking Water Quality From Water Coolers in Makkah, Saudi Arabia

The quality of drinking water is an important health issue in crowded cities, so that an adequate drinking water with good quality must be provided, hence over hundreds of water coolers are distributed in Makkah city to cope with the increasing demand for drinking water. The present study aimed to determine the chemical and microbial quality of drinking water from coolers in Makkah city. Sixty-three samples from randomly selected water coolers were tested for chemical and bacteriological quality. For all samples, the mean value of physiochemical tests of pH (7.12), TDS (152.7 ppm), turbidity (2.56 NTU), free chlorine (0.312 ppm), fluoride (0.112 ppm), chloride (25.7 ppm), bromide (0.123 ppm), nitrate (0.616 ppm), sulfate (8.36 ppm), lithium (0.134 ppm), sodium (17.6 ppm), potassium (1.42 ppm), magnesium (1.95 ppm), calcium (19.2 ppm), chromium (0.025 ppm), cadmium (0.0026 ppm), and lead (0.0244 ppm) did not exceed the reference values of the drinking water regulations. The total coliform count was detected in 3.2% of the water samples. For total coliform count, the MPN in the majority of water samples (96.8%) was excellent while for E. coli count, the MPN in all water samples (100%) was excellent. Bacteriological quality has shown that no Pseudomonas, Salmonellae, or Legionellae species contamination detected. It was concluded that, the drinking waters in coolers in Makkah city were complied with international standards and within the acceptable limit. It is worth to continue periodic inspection and maintenance for the drinking water coolers during mass gatherings.