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Background: Arsenic, a contaminant of groundwater and irrigated crops, is a global public health hazard. Exposure to low levels of arsenic through food extends well beyond the areas with high arsenic water content. While isolated impairments of cognitive function following chronic exposure to high arsenic levels have been described, a comprehensive assessment of the scope of such impairments and their underlying brain mechanisms does not exist, especially not in the case of the much more common low-level arsenic exposure. Methods: We analyse 1014 participants aged 6 to 23 years of the Indian Consortium-on-Vulnerability-to-Externalizing-Disorders-and-Addictions (cVEDA). Participants were characterised using deep phenotyping measures of behaviour, neuropsychology, psychopathology, brain neuroimaging and exposure to developmental adversities and environmental neurotoxins. Arsenic was measured in urine as an index of exposure. Findings: Using sparse-partial least square analysis (sPLS) we describe a correlation of arsenic exposure with impairments in executive function (r=-0.12, p=5.4x10-4), brain structure (r=-0·2, p=1·8x10-8) and functional connectivity (within-network: r=-0·12, p=7·5x10-4, between-network: r=-0·23, p=1·8x10-10). Impairments in executive function were partially mediated by localised changes in grey-matter volume (b=-0·004, CIs=-0·007 to -0·002) and within-network functional connectivity (b=-0·004, CIs=-0·008 to -0·002). Socio Economic Status (SES) and Body Mass Index (BMI) moderated the link between arsenic and changes in grey-matter volume, with the effect of arsenic being strongest in participants from lower SES and with low BMI. Interpretation: We describe a syndrome of impairments in executive function and their brain correlates associated with low-level arsenic exposure. Our results demonstrate detrimental consequences of arsenic exposure well below currently recommended guidelines that affects people beyond endemic risk areas. Precision medicine approaches to study global-mental-health vulnerabilities, highlight widespread but potentially modifiable risk factors and a mechanistic understanding of the impact of low-level arsenic exposure on brain development. Funding Information: Indian Council for Medical Research and Medical Research Council, United Kingdom. Declaration of Interests: All authors report no competing interests. Ethics Approval Statement: The cVEDA Study was approved by the Health Ministry Screening Committee, Ministry of Health and Family Welfare, Government of India. The study protocol was approved by the Institutional Ethics Review Boards of National Institute of Mental Health and Neurosciences (NIMHANS) Bangalore, India (Item No. VII, SI. No. 7·08, Behavioural Sciences) and all other regional collaborating institutions. Informed consent was obtained from participants over the age of 18 and from parents of participants under 18 years of age (along with assent from minor participants).

Background: Combustion of traditional biomass fuels and coal has been found to be associated with exposure to particulates and volatile organic compounds (VOCs) and cause a series of adverse health effects. Characterization-quantification of such exposure achieved so far is not optimum, and establishment of a protective mechanism with proven efficacy is the urgent need. Methods: The present study was planned to characterize exposure from fuel during cooking in a village of India and understand the effect of using intervention measure. In this study, exposure to different pollutants was examined by personal monitoring in different cooking arrangements with traditional and modified oven. Results: It is observed that level of the pollutants has lessened by several folds while cooking with modified oven in comparison to unmodified oven. Such change of pollutants levels with the use of modified oven was found to be statistically significant in cases of benzene (P < 0.001), toluene (P < 0.01), and particulates (P < 0.0001). Conclusions: This study highlights the exposure from indoor air pollution during cooking and promotes use of low-cost protective mechanisms to curb resulting human health adversities. This study also calls for concerted awareness generation activity among the rural population (especially women) regarding adverse health effect of cooking fuels and protective effect of installed mechanisms.

This study focused work-exposure to particulate matter ≤ 10 µm (PM10), volatile organic compounds (VOCs) and biological monitoring of major VOCs (BTEX) to observe the significant effects of traffic related pollutants on respiratory and hematological systems of workers engaged in two occupational settings, petrol pumps and traffic areas of Kolkata metropolitan city, India. PM10 was assessed by personal sampling and particle size distribution by 8-stage Cascade Impactor. VOCs were analysed by gas chromatography-flame ionization detector (GC-FID) and five urinary metabolites, trans trans- mercapturic acid (tt-MA), S-phenyl mercapturic acid (SPMA), hippuric acid (HA), mandelic acid (MA) and methyl hippuric acid (MHA) of VOCs, benzene, toluene, ethyl benzene and xylenes (BTEX) by reverse phase high performance liquid chromatography (HPLC). Pulmonary functions test (PFT) was measured Spirometrically. ∂-aminoleavulinic acid (ALA) and porphobilinogen (PBG) in lymphocytes were measured spectrophometrically following column chromatographic separation. High exposure to PM10, having 50% of particles, ≤ 5.0 µm in both the occupational settings. Exposure to toluene was highest in petrol pumps whereas benzene was highest (104.6 ± 99.0 μg m-3) for traffic police personnel. Workplace Benzene is found many fold higher than the National ambient standard. Air-benzene is correlated significantly with pre- and post-shift tt-MA (p < 0.001) and SPMA (p < 0.001) of exposed workers. Blood cell counts indicated benzene induced hematotoxicity. ALA and PBG accumulation in lymphocytes indicated alteration in heme-metabolism, especially among traffic police. Significant reduction of force exploratory volume in one second (FEV1) and forced vital capacity (FVC) of fuel fillers are observed with increased tt-MA and SPMA. Study revealed PFT impairments 11.11% (6.66% restrictive and 2.22% obstructive and combined restrictive and obstructive type, each) among petrol pumps and 8.3% obstructive type among traffic police.

Aim: This study aimed to establish liquid–liquid extraction (LLE) for estimation of hippuric acid (HA) in urine as a biomarker of the toluene exposure by high-performance liquid chromatography equipped with photodiode array detector (HPLC-PDAD). Method: HA in urine was extracted by LLE and determined by HPLC-PDAD. The operating conditions with HPLC were ODS-2 hypersil column (250 mm × 4.6 mm, 5 μm), 0.1% trifluoro acetic acid (TFA) in acetonitrile and 0.1% TFA in water as mobile phase, 1 ml/min flow rate, and wavelength of 205 nm. The validity of the present method was tested by the estimation of HA in urine samples, collected from toluene-exposed (shoe workers) and unexposed or control subjects. Results: Binary gradient system was used to achieve optimum separation. The analytical curve prepared for HA in aqueous solution in the range of 0.5–10 μg/ml showed determination coefficient value (R2) 0.998. Limit of detection and quantification (LOQ) were 0.46 and 1.53 μg/ml, respectively. The coefficients of variance for intraday precision were 1.4% for HA standard (5 μg/ml) and 1.1% for pooled urine, whereas inter-day precision values were 3.2% and 4.9% for HA standard and pooled urine, respectively. Method recovery obtained was 96%–120% for HA solutions containing 2, 3, and 5 μg/ml, demonstrating that precision and recovery of method were satisfactory. Compared to unexposed group, exposed group had significantly more HA. It was found significantly (P < 0.05) higher in urine of exposed workers (32.52 ± 10.91) than unexposed group (16.21 ± 10.14). Conclusion: Sample preparation by LLE is simple and cost-effective for the determination of HA as a biomarker of toluene exposure by HPLC-PDAD. It can be used to detect HA in urine for population exposed to toluene.

This study focused work-exposure to particulate matter ≤ 10 µm (PM