Health Risks Of Exposure Research Articles

Antioxidative Function of Zinc and Its Protection Against the Onset and Progression of Kidney Disease Due to Cadmium

Chronic kidney disease (CKD) is now the world’s top seventh cause of death from a non-communicable disease, and its incidence is projected to increase further as its major risk factors, including obesity, diabetes, hypertension, and non-alcoholic fatty liver disease (NAFLD), continue to rise. Current evidence has linked the increased prevalence of CKD, diabetes, hypertension, and NAFLD to chronic exposure to the metal pollutant cadmium (Cd). Exposure to Cd is widespread because diet is the main exposure route for most people. Notably, however, the health risk of dietary Cd exposure is underappreciated, and the existing tolerable exposure guidelines for Cd do not afford health protection. New health-protective exposure guidelines are needed. From one’s diet, Cd is absorbed by the intestinal epithelium from where it passes through the liver and accumulates within the kidney tubular epithelial cells. Here, it is bound to metallothionine (MT), and as it is gradually released, it induces tubular damage, tubulointerstitial inflammation and fibrosis, and nephron destruction. The present review provides an update on our knowledge of the exposure levels of Cd that are found to be associated with CKD, NAFLD, and mortality from cardiovascular disease. It discusses the co-existence of hypertension and CKD in people environmentally exposed to Cd. It highlights nuclear and mitochondrial targeting and zinc deficiency as the universal cytotoxic mechanisms of Cd. Special emphasis is placed on the novel antioxidative function of zinc involving de novo heme biosynthesis and the induced expression of heme oxygenase-1 (HO-1). Other exogenous biomolecules with promising anti-Cd toxicity are highlighted.

Integrated Metabolomic and Transcriptomic Analysis Revealed the Mechanism of BHPF Exposure in Endometrium

Fluorene-9-bisphenol (BHPF) has been increasingly used as a bisphenol A substitute in the synthesis of various products. Previous studies have suggested that BHPF can be released from plastic bottles into drinking water, and BHPF accumulation has been reported to cause various adverse effects in humans. Nevertheless, the impact of BHPF exposure on endometrial epithelial cells remains largely unexplored. Here, we investigated the effects of exposure to different concentrations of BHPF on endometrial cells and used integrated metabolomic and transcriptomic methods to elucidate the underlying molecular mechanisms. Our results revealed significant associations between specific metabolites and genes, indicating that low-concentration exposure to BHPF affects endometrial epithelial cells by targeting pathways related to primary immunodeficiency, in which the key genes are IL7R and PTPRC. High-concentration exposure to BHPF decreased cell viability by regulating the purine metabolism pathway, as well as dysregulating the expression of PGM1, PDE3B, AK9, and ENTPD8. Our study highlights that the health risk of BHPF exposure to endometrial epithelial cells is concentration-dependent and that integrated analysis of metabolomic and transcriptomic data not only revealed the biological effects of BHPF and its underlying mechanisms, but also provided key candidate target genes for further exploration.

Regulatory Trends of Organophosphate and Pyrethroid Pesticides in Cannabis and Applications of the Comparative Toxicogenomics Database and Caenorhabditis elegans.

Organophosphate and pyrethroid pesticides are common contaminants in cannabis. Due to the status of cannabis as an illicit Schedule I substance at the federal level, there are no unified national guidelines in the U.S. to mitigate the health risk of pesticide exposure in cannabis. Here, we examined the change in the state-level regulations of organophosphate and pyrethroid pesticides in cannabis. The medians of pyrethroid and organophosphate pesticides specified by each state-level jurisdiction increased from zero pesticide in 2019 to 4.5 pyrethroid and 7 organophosphate pesticides in 2023, respectively. Next, we evaluated the potential connections between pyrethroids, organophosphates, cannabinoids, and Parkinson's disease using the Comparative Toxicogenomics Database (CTD). Eleven pyrethroids, 30 organophosphates, and 14 cannabinoids were associated with 95 genes to form 3,237 inferred and curated Chemical-Gene-Phenotype-Disease tetramers. Using a behavioral repulsion assay with the whole organism model Caenorhabditis elegans, we examined the effect of cannabinoids and insecticides on depleting dopamine synthesis. Exposure to chlorpyrifos and permethrin, but not Δ9-tetrahydrocannabinol (THC) and cannabidiol (CBD), results in dose-dependent effects on 1-nonanol repulsive behaviors in C. elegans, indicating dopaminergic neurotoxicity (p < 0.01). Dose-dependent effects of chlorpyrifos are different in the presence of Δ9-THC and CBD (p < 0.001). As a proof of concept, this study demonstrated how to use new approach methodologies such as C. elegans and the CTD to inform further testing and pesticide regulations in cannabis by chemical class.

Potential Health Risks of Exposure to Graphene and Its Derivatives: A Review

Graphene and its derivatives (GDs) have been applied in many fields, like photocatalysts, sensors, and biomedical delivery, due to its excellent physicochemical properties. However, the widespread use of GDs has significantly increased human exposure to these materials. Some health risks of exposure to GDs have been identified, including organ fibrosis, inflammation, DNA damage, etc. Given that graphene is a novel concern, we especially emphasized the various exposure pathways and potential health risks of exposure to GDs. People get exposed to GDs mainly through inhalation, ingestion, dermal contact, etc. GDs could transfer to the circular system of people and accumulate in blood, cells, and major organs. GDs exposure could induce organ and cell inflammatory responses and damage, such as disrupted kidney function, declined cell vitality, cytotoxicity, etc. These changes at the organ and cell levels might lead to adverse tangible influences on people, like decreased locomotor activity, the accelerated aging process, and even abnormal offspring development. We also summarized the characterization and detection methods of GDs. In addition, we compared the studies of exposure to dust and GDs in the aspects of health risks and study methods. This review could offer a comprehensive summary related to GDs and provide helpful references for further graphene-related studies.

Novel Insights into Hg0 Oxidation in Rice Leaf: Catalase Functions and Transcriptome Responses.

Rice leaves can assimilate atmospheric mercury (Hg0), which is accumulated by grains and causes health risks to rice consumers. However, the molecular mechanisms underlying Hg0 assimilation in rice leaves remain poorly understood. Here, we investigated catalase's (CAT) function in Hg0 oxidation within rice leaves, as well as the Hg speciation and transcriptomic profiles of rice leaves exposed to Hg0. The inactivation of catalase reduced Hg0 oxidation by 91% in the leaf homogenate and the Hg0 oxidation rate increased along with CAT activity, showing the CAT's function in Hg0 oxidation. Hg0 was converted to Hg(cysteine)2 complexes in the leaf. Transcriptomic results revealed that the expression levels of both OsCATA and OsCATB (catalase-encoding genes) increased with Hg concentration, suggesting the involvement of catalase-related molecular network in Hg0 oxidation. Upstream transcription factors, including NAC (NAM-no apical meristem, ATAF-Arabidopsis transcription activation factor, and CUC-cup-shaped cotyledon), and ethylene-responsive transcription factor, are likely involved in catalase expression. Genes related to cysteine metabolism and amino acid transport appeared to regulate Hg accumulation. Our findings demonstrate the important function of catalase in Hg0 oxidation within rice and are fundamental for developing genetically modified rice cultivars to minimize human Hg exposure health risks.

Unveiling potential biomarkers and associated health risks of chronic experimental exposure to environmentally relevant concentration of Metalaxyl: An untargeted metabolomics approach

Unveiling potential biomarkers and associated health risks of chronic experimental exposure to environmentally relevant concentration of Metalaxyl: An untargeted metabolomics approach

Occupational health risk assessment and risk monetization based on xylene exposure.

The risk evaluation of occupational exposure to xylene was conducted to provide a basis for the formulation of policies on the prevention and control of occupational hazards of xylene and to fill the gap in this field. In this study, a number of xylene-related companies in seven industries from 2020 to 2023 were collected as research subjects, and the health risks caused by xylene exposure were evaluated using the EPA model designated by the U.S. Environmental Protection Agency, the Singapore Semi-Quantitative Risk Assessment Model (MOM), and the International Council on Mining and Metals (ICMM) Occupational Health Risk Assessment Model. Subsequently, a risk monetization method was used to convert the health risks of xylene exposure into currency. the results of the study showed that the EPA and MOM models were more reasonable and could accurately identify occupational health risks due to xylene exposure, while the ICMM model overestimated the health risks due to xylene exposure by assessing the risk level of all industries as level 4 or higher. Incorporating the number of people on the job into the risk assessment can differentiate the number of people involved in the health risks caused by xylene exposure, which is more conducive to the adoption of targeted preventive and control measures. The risk monetization model can provide a more intuitive view of the direct economic losses that may be caused by occupational exposure to xylene, which can help the relevant authorities to formulate strategies for the prevention and control of xylene hazards, and also provide a strong support for occupational damage compensation.

Perfluorohexane sulfonate exposure caused multiple developmental abnormalities in early life of zebrafish

Perfluorohexane sulfonate (PFHxS) has been listed as a new persistent organic pollutant since 2022. Although the production and use of PFHxS are now restricted, it remains highly persistent in aquatic environments for decades. However, so far research about the toxic effects on early-life exposure of PFHxS and underlying mechanisms are still limited. In this study, we employed both wild type and specifically labeled transgenic zebrafish as model to investigate the developmental toxicity of PFHxS during early-stage exposure in zebrafish. A series of phenotypic and molecular indicators were analyzed at various time points between 24 hours post-fertilization (hpf) and 7 days post-fertilization (dpf). Our data showed that the acute toxicity of PFHxS was much lower than PFOS, with a lethal concentration 50% of 508.11 ± 88.54 μM at 120 hpf. Low-dose PFHxS exposure significantly altered heart rates, blood flow, and swimming behavior in zebrafish larvae, suggesting potential cardiotoxicity and neurotoxicity of zebrafish. Data from transgenic zebrafish with specifically labeled hearts (CZ40) confirmed that PFHxS affects cardiovascular system development. PFHxS-induced changes in transgenic zebrafish with labeled liver and pancreas (CZ16) suggest that PFHxS may cause metabolic disorders and contribute to developmental defects. Gene expression analysis showed that PFHxS with potential estrogenic effect might also affect the gonadal development of zebrafish. Our study can offer an insight into the toxicity of PFHxS in aquatic environment and health risks of early-stage PFHxS exposure in humans.

Investigation of the spatial variation of ambient air VOCs and their effects on the health risk caused by long-term exposure in urban area

ABSTRACT Long-term exposure to Volatile Organic Compounds (VOCs) is a health risk for citizens. In this study, the cumulative health risk of exposure to VOCs in Tehran was assessed by investigating the concentration of these pollutants in ambient air in a five-year period. Health risk assessment was calculated by the quantitative method and the carcinogenic risk level was determined using the lifetime carcinogenic risk (LCR) method. The average concentration of benzene, toluene, ortho-xylene, and ethylbenzene was 1.4–1.8, 4.8–5.4, 5–6.5, and 3.6–4 ppb, respectively. Although HQ was not greater than 1, but it was very close in the case of benzene, ortho-xylene, meta-xylene, and para-xylene. Benzene and ethylbenzene had the largest effect in the assessed health risk. So the long-term exposure of Tehran citizens to VOCs has serious health consequences for them, which could be different according to the exposure time and spatial variations.

Comprehensive Assessment of the Health Risk of Cadmium Exposure from Soil-wheat System in Wheat Fields in Northern China

Accurately assessing the health risks of cadmium （Cd） exposure in the soil-wheat system is of great importance for the formulation of regional health risk prevention measures. Based on regional large-scale survey and Monte Carlo simulation methods, a case study on the health risk of Cd exposure in a soil-wheat system in a wheat production area of North China Plain was conducted by constructing a comprehensive health risk assessment （CHRA） model. The results showed that 73% of the soil samples in the study area exceeded the screening value of Cd for farmland soil （GB 15618-2018） and 57.8% of the wheat samples exceeded the national standard （GB 2762-2017） for Cd. The hand-mouth ingestion pathway was the main route of soil Cd exposure for adults and children in the region, and under this pathway, 34.7% of adults and 57.4% of children had a cancer risk higher than the safe threshold recommended by USEPA （1E-06）. The comprehensive non-carcinogenic and carcinogenic risks of cadmium exposure from the soil-wheat system in the region were higher than the safe domain values for both adults and children, with the probabilities of 26.4% and 100% for adults and 62.5% and 100% for children, respectively. The overall trends of the comprehensive risks showed that children had higher risks than those of adults. The combined application of the comprehensive health risk assessment model and the uncertainty random simulation method helps to improve the accuracy of risk decision-making.

Determining Radon Gas Concentration in Teeth Samples of Adults in Al-Najaf Governorate in Iraq

Background: Radon is a naturally occurring radioactive gas that can accumulate in the environment and pose health risks to residents. Exposure to radon gas increases the risk of lung cancer. Although extensive research has been conducted on radon levels in residential and occupational settings, little attention has been given to radon concentrations in dental materials. Objectives: This study determines the concentration of radon gas in dental samples collected from the adult population in Najaf Governorate, Iraq. Accordingly, the primary objective of this study is to measure the concentration of radon gas in dental samples collected from residents of Najaf Governorate and to assess whether these levels pose any health risks according to established guidelines. Methods: A total of 40 dental samples were collected from individuals aged between 18 to 85 years residing in different areas of Najaf Governorate, Iraq. The concentration of radon gas in the dental samples was measured using nuclear trace detectors. These detectors are sensitive to α particles emitted by radon gas, allowing for accurate measurement of radon concentrations in the samples. Results: The average concentration of radon gas in the analyzed dental samples was 74.2±9.6 Bq/kg. This value was within the normal range for radon levels in dental samples and below the reference level of 100 Bq/kg recommended by the International Commission on Radiological Protection (ICRP). Nevertheless, a significant percentage of dental samples contained detectable levels of radon gas, and some samples had concentrations that exceeded the recommended limits. Conclusion: Radon concentrations in dental samples taken from adults in Najaf Governorate, Iraq, did not raise any major radiological health concerns; however, the presence of detectable levels of radon in some samples highlights the need for further research to understand the potential health risks of radon exposure in dental materials. The findings also underscore the importance of routinely monitoring radon levels in dental settings and implementing better safety precautions to protect dental professionals and patients.

Radiological Health Risk of Exposure to Gamma Radiation in Private Diagnostic Center in Khana Local Government Area Rivers State, Nigeria

The &amp;lt;i&amp;gt;In-situ&amp;lt;/i&amp;gt; measurement of background ionizing radiation of Centre of Life hospital Bori in Khana Local Government Area of Rivers state of Nigeria has been carried out. Digilert-200 Radiation meters was utilized in measurement of background ionizing radiation and Global Positioning System (Garmin 765) was used in measuring coordinates of the sampling points. Fifteen (15) sampling points were arbitrarily selected within the diagnostics centre. The results of the BIR outdoor and indoor varies from 0.010 - 0.015 with mean of 0.013 mRhr-1. Absorbed Dose rate varies from 87.0 -130.5 nGy/yr with mean of 114.3 nGy/yr and 116.0 nGy/yr for outdoor and indoor. AEDE varies from 0.107 – 0.160 with mean of 0.140 mSv/yr and 0.142 mSv/yr and Excess life cancer risk varies from 0.37×10-3 – 0.56×10-3 with mean of 0.50×10-3 and 0.50×10-3 for outdoor and indoor respectively. The obtained values for BIR of Centre of Life Hospital Ltd was within recommended standard limit of 0.013mR/h. The obtained result for AEDE was within the recommended safe limit. The obtained results of ELCR and the ADR are all higher than the recommended standard of 0.29 x 10-3 and 84.0 nGy/h respectively. The result of radiation dose to different body organ shows that the testes have the highest radiation percentage for outdoor and indoor respectively.

Pollution characteristics and health risk assessment of heavy metals in PM2.5 in Fuxin, China

Fuxin is located in the atmospheric channel around Bohai Bay, and its geographical location is very special. Few existing studies have investigated the pollution characteristics and health risk assessment of heavy metals in atmospheric PM2.5 during the four seasons in Fuxin, so a total of 180 PM2.5 samples were collected from four sampling sites in Fuxin from December 2021 to November 2022. The seasonal distribution characteristics of V, Cr, Mn, Co, Ni, Cu, Zn, Pb, As, Sb, Cd and Ba were analysed via inductively coupled plasma-mass spectrometry (ICP‒MS), and the source of the heavy metals was analysed via the enrichment factor (EF) and principal component analysis (PCA). A health risk model was used to assess the health risk of respiratory exposure in men, women and children in Fuxin. The results revealed that the annual average mass order of heavy metals in Fuxin PM2.5 was Zn (0.2947 μg·m−3) > Pb (0.0664 μg·m−3) > As (0.0225 μg·m−3) > Ba (0.0205 μg·m−3) > Mn (0.0187 μg·m−3) > Cu (0.0140 μg·m−3) > Cr (0.0095 μg·m−3) > V (0.0067 μg·m−3) > Ni (0.0061 μg·m−3) > Sb (0.0024 μg·m−3) > Cd (0.0019 μg·m−3) > Co (0.0007 μg·m−3). The annual average concentration of As was 3.75 times the GB3095-2012 (China) secondary standard limit, and the concentration of hazard quotient (HQ) in PM2.5 was lower than 1, but the concentration of incremental lifetime cancer risk (ILCR) in As was higher than the cancer risk threshold (10–4). These findings indicate a certain risk of cancer in the urban population of Fuxin. Therefore, it is necessary to control the emissions created from coal burning to minimize the health risks to the people of Fuxin.

A Decade-Long Comparison of Heavy Metal(loid)s in the River and Children’s Health Risk Assessment of an E-Waste Recycling Area

Informal e-waste recycling can cause serious heavy metal(loid) pollution to nearby bodies of water, thereby increasing the risk of heavy metal exposure to local residents. This study investigates metal(loid) pollution levels in the Lianjiang River, which flows through Guiyu, an e-waste recycling town in Shantou, Guangdong. In 2009 and 2020, water samples from the Lianjiang River were taken, and the levels of 12 metal(loid)s (V, Cr, Mn, Sr, Ni, Cu, Zn, As, Se, Cd, Ba, and Pb) were measured by ICP-MS. In total, 380 valid questionnaires from Guiyu kindergarten children were selected to assess child health. Exposure health risks for children were calculated using two forms of exposure (dermal and inhalation) and statistical methods (multiple linear regression and Bayesian kernel machine regression—BKMR). The concentrations of Mn, Ni, Pb, and Cd in 2009 were significantly higher than those in 2020. The concentration of heavy metal(loid)s had been decreasing in 2020. The non-carcinogenic risk levels of the 12 metal(loid)s in both exposure routes were at an acceptable risk level. The average carcinogenic risk levels for As, Cr, Ni, Pb, and Cd exceeded the ILCRi &lt;10–6 acceptable range. According to MLR, it was found that daily oral intake doses of Pb [β(95% CI): −0.949 (−1.596, −0.863), p &lt; 0.001 and Se [β(95% CI): −0.911 (−1.888, −0.092), p = 0.031] were negatively associated with body mass index. A BKMR model was developed, through which the synergistic effects of co-exposure to 12 heavy metal(loid)s on growth and development indicators in children were analyzed. Concentrations of heavy metal(loid)s in rivers near e-waste recycling sites have been decreasing for 10 years. It was found that the growth and development of children are affected by the intake of heavy metal(loid)s in water. The reduction in heavy metal(loid) contamination in e-waste recycling areas needs to be continued, and concern about its impact on children’s health must remain.

Assessing metals and metalloids impact of roadside dust on human health in Osogbo, Osun state, Nigeria

BackgroundMetals and metalloids in roadside dust pose considerable threats to both human health and the environment. ObjectivesThis study assesses human health risks of metal exposure to roadside dust by conducting a health risk assessment (HRA) for metals and metalloids uptake rates for children and adults via exposure pathways. MethodsSettled dust samples were collected from the major roads in Osogbo, Osun state. These samples were subjected to standard laboratory procedures for metals and metalloids analysis using Atomic Absorption Spectroscopy (AAS). ResultsAll the metals and metalloids except Cd had their concentration below the WHO limit. The average concentration of Cd was 1.54 mg kg-1, significantly above the WHO guideline of 0.80 mg kg-1, indicating a possible health concern. A strong positive correlation exits between Ni and Cd (0.774⁎⁎) (p < 0.01), Pb (0.662⁎⁎) (p < 0.01), Zn (0.606⁎⁎) (p < 0.01), and as (0.549*) (p < 0.05), showing that greater Ni concentrations are associated with higher concentrations of Cd, Pb, Zn, and As. Two principal components were identified, accounting for 80 % of the overall variation. PC1 has an eigenvalue of 60.834; however, PC2 has a higher eigenvalue of 74.952, implying that PC2 explains more of the variation in the data than PC1. Non-carcinogenic risk evaluations identify possible health risks linked with Cu, Cd, Cr, and As exposure, primarily through inhalation routes. Carcinogenic risk showed that Cd demonstrated high CR values ranging from 3740 to 1.30×1012 for adults and children throughout the study's various exposure paths. ConclusionThis study offered significant insight into the metals and metalloids pollution status in Osogbo, Nigeria, employing data and statistics, highlighting the need for evidence-based actions for environmental preservation to safeguarding people's health.

Potential health risk of human exposure to tobacco-specific nitrosamines in second-hand and third-hand smoke

Environmental tobacco smoke (ETS), including both second-hand (SHS) and third-hand smoke (THS), seriously impacts human health. However, the potential health risk of non-smokers’ exposure to ETS (especially THS) has not been fully characterized. The present study conducted smoking events in a 100 m³ room. Gaseous and size-fractioned particulate samples from SHS and THS along with wipe samples on desk and floor surfaces were collected and analyzed for tobacco-specific nitrosamines (TSNAs). The concentration, composition, and size distribution of indoor TSNAs varied between SHS and THS due to variability in particle deposition, air exchange, chemical reaction, and partitioning. Children had higher per body weight daily intake of TSNAs and nicotine through all exposure pathways than other population groups. The contributions of different exposure pathways to the intake of pollutants were influenced by their octanol-air partition coefficients. Incremental lifetime cancer risk (ILCR) for different population groups from exposure to residential TSNAs in ETS exceeded 1.0 × 10−6, even with exposure to THS only. The ILCR from e-cigarettes was lower than that from cigarettes, but it still posed potential carcinogenic risk, particularly through air-to-skin transdermal exposure to THS. Reducing health risk for exposure to both SHS and THS requires rigorous enforcement of smoking-free policies.

Consumer Safety and Pesticide Residues: Evaluating Mitigation Protocols for Greengrocery.

The application of pesticides remains a necessary measure for pest management in agriculture, particularly in the cultivation of fruits and vegetables. After harvest, the presence of pesticide residues in greengrocery (fruits and vegetables) is significantly influenced by various factors, including storage conditions, handling practices, and subsequent processing methods. The mitigation of these residues to levels compliant with regulated maximum thresholds ensures the safety of raw and processed fruits and vegetables for consumption. A contemporary survey of pesticide residues in greengrocery has gathered considerable attention from consumers, driven by concerns over the potential health risk of pesticide exposure. Consequently, consumers want to be extensively informed about household processing techniques to minimize associated risks. Meanwhile, a critical question arises: does household processing effectively eliminate pesticide residues? A comprehensive review of the literature reveals that conventional methods, such as washing and soaking, offer only limited reduction in residue levels, while emerging treatments, suitable both at household and industrial scale, demonstrate increased efficiency in residues mitigation. This study aims to emphasise the ubiquitous use of pesticides in crop cultivation while providing recommendations for the implementation of efficient treatment protocols to address residue concerns. Following upon available evidence and database mining, the worldwide purpose must be to outline agriculturally and economically viable strategies that prioritize both the health and safety of consumers, as well as the green cultivation and processing of fruits and vegetables.

An inhalation exposure assessment of Hexafluoroisobutylene in pregnant rats

Hexafluoroisobutylene (HFIB) is an important compound widely used in semiconductor lithography materials, refrigerants, fluorine coatings, and pharmaceutical intermediates in the fluorination industry. Owing to its toxicity, the occupational exposure in the workplace, especially for pregnant woman is the concern and there is still lack of the data of HFIB toxicity on pregnancy and fetal development. Here, for the first time, we investigated the effects of HFIB on pregnant rats and fetal development. The pregnant rats were exposed to different doses of HFIB (0 ppm, 27.2 ppm, 53.5 ppm, 105.6 ppm) via whole-body inhalation for the period of organogenesis, which from implantation (gestation day 5) to the day prior to scheduled caesarean section (gestation day 19). The results showed that the pregnant rats exposed to 105.6 ppm HFIB displayed systemic toxicity, including a decrease in body weight and food consumption, as well as tracheal inflammation, pulmonary interstitial inflammation and renal tubular swelling. Moreover, reduced fetal and placental weights, delayed ossification, and a reduced number of ossification centers were observed in fetuses delivered by pregnant rats exposed to 105.6 ppm. These effects were attributed to severe maternal weight loss. In addition, it would be useful to note that no whole-body, visceral or skeletal congenital malformations were observed. However, HFIB exposure at 53.5 ppm showed no significant adverse effects on pregnant rats and fetuses. These findings demonstrate that 105.6 ppm HFIB is a toxic concentration, while 53.5 ppm HFIB is the no-observed-adverse-effect concentration (NOAEC) for both pregnancy and fetal development. This study for the first time to provide evidence for the health risk of HFIB exposure on pregnancy and fetal development.

Human health risk of exposure to potentially toxic metals (PTMS) in indoor settled dusts from selected worship centres (WCS)

The study aimed to determine the concentration of potentially toxic metals (PTMs) and the health risk of exposure to indoor dust from worship centres in Abeokuta, Nigeria. Twenty-four (24) dust samples were collected from various corners of selected worship centres. One (1) gram of the sieved dust was digested using aqua regia. PTM analyses were done using an Atomic Absorption Spectrometer (AAS). The result revealed the presence of Iron (Fe)&gt; Zinc (Zn)&gt;Manganese (Mn)&gt; Lead (Pb) &gt; Copper (Cu) &gt;Nickel (Ni) &gt; Cadmium (Cd) (1050; 81.6; 72.5; 3.304; 2.43; 0.516; 0.076 mg/kg) respectively. The PTMs were within the permissible limit for PTMs in dust stated by UK and Dutch Intervention. Pollution indices revealed Zn as the primary pollutant in the dust. A significant association between Zn, Cu, Ni and Cd while that of Mn and Fe suggest a common origin of anthropogenic and lithogenic sources respectively (p&lt;0.01). Health risk assessment revealed inhalation as the major pathway of PTM exposure with the children population being the most susceptible. Hazard index (HI) values were &lt;1, showing a non-significant non-cancer effect on exposure while the cancer risk estimate shows no carcinogenic risk. Conclusively, the selected worship centres have no PTM concentration of health concern at the time of the investigation. However, regular wet cleaning and close monitoring of the worship centres should be considered.

Spatial distribution and risk assessment of perchlorate in raw cow milk from China

Perchlorate is a ubiquitous environmental contaminant worldwide, recognized as an emerging thyroid toxicant. This study focused on the pollution status, spatial distribution, possible sources of perchlorate in raw cow milk collected from 155 dairy farms in China, as well as the health risk of exposure to perchlorate through dairy products. The results showed that the detection rate of perchlorate in raw milk was 100% with the mean of 15.9 μg/kg, indicating the ubiquitous contamination of perchlorate in raw milk from China. The simulation of spatial distributions indicated that the levels of perchlorate in raw milk were spatially correlated, and relatively high levels of perchlorate exist in certain parts of Beijing-Tianjin-Hebei, Shanxi, Henan, and Zhejiang, suggesting potential environmental perchlorate contamination in these regions. A positive correlation was found between the perchlorate level in milk and the perchlorate level in feed, indicating the transfer process of perchlorate from feed to milk. The hazard quotient (HQ) values of exposure to perchlorate by dairy products ranged between 0 and 2.14, with the mean of 0.0188 and P95 of 0.101, indicating relatively low health risk to perchlorate through dairy products. To our knowledge, this is the first nationwide study on the spatial distribution and risk assessment of perchlorate in raw cow milk from China.