Survey of arsenic in food composites from an arsenic-affected area of West Bengal, India

Effects of silicon (Si) on arsenic (As) accumulation and speciation in rice (Oryza sativa L.) genotypes with different radial oxygen loss (ROL)

Arsenic (As) contamination of paddy soils has adversely affected the health of millions of people those consuming rice for staple food. The present study was aimed at investigating the effects of silicon (Si) fertilization on As uptake, speciation in rice plants with different radial oxygen loss (ROL). Six genotypes were planted in pot soils under greenhouse conditions until late tillering state. The results showed that the rates of ROL were higher in hybrid rice genotypes varying from 19.76 to 27 μmol O2 g(-1) root dry weight h(-1) than that in conventional indica rice genotypes varying from 9.55 to 15.41 μmol O2 g(-1) root dry weight h(-1). Si addition significantly increased straw biomass (p<0.005), but with no significant effects on root biomass. Si fertilization significantly reduced shoot and root total As concentrations (p<0.001) in six genotypes grown in 40 mg As/kg soil. Si addition decreased the inorganic As in shoots of 'Xiangfengyou-9' with lower ROL and 'Xiangwanxian-12' with higher ROL by 31% and 25% respectively and had the tendency to increase DMA concentrations. It is potential to reduce As contamination of rice efficiently by combining Si fertilization and selecting genotypes with high radial oxygen loss.

Assessment of toxic metals in groundwater and saliva in an arsenic affected area of West Bengal, India: A pilot scale study

Communities in many parts of the world are unintentionally exposed to arsenic (As) and other toxic metals through ingestion of local drinking water and foods. The concentrations of individual toxic metals often exceed their guidelines in drinking water but the health risks associated with such multiple-metal exposures have yet to receive much attention. This study examines the co-occurrence of toxic metals in groundwater samples collected from As-rich areas of Nadia district, West Bengal, India. Arsenic in groundwater (range: 12-1064 µg L(-1); mean ± S.D: 329±294 µg L(-1)) was the most important contaminant with concentrations well above the WHO guideline of 10 µg L(-1). Another important toxic metal in the study area was manganese (Mn) with average concentration of 202±153 µg L(-1), range of 18-604 µg L(-1). The average concentrations (µg L(-1)) of other elements in groundwater were: Cr (5.6±5.9), Mo (3.5±2.1), Ni (8.3±8.7), Pb (2.9±1.3), Ba (119±43), Zn (56±40), Se (0.60±0.33), U (0.50±0.74). Saliva collected from the male participants of the area had mean concentrations of 6.3±7.0 µg As L(-1) (0.70-29 µg L(-1)), 5.4±5.5 µg Mn L(-1) (0.69-22 µg L(-1)), 2.6±3.1 µg Ni L(-1) (0.15-13 µg L(-1)), 0.78±1.0µg Cr L(-1) (<DL-5.9 µg L(-1)), 0.94±0.90 µg Pb L(-1) (<DL-4.2 µg L(-1)), 0.56±0.37 µg Se L(-1) (0.11-1.5 µg L(-1)) and 194±54 µg Zn L(-1) (112-369 µg L(-1)). The high concentrations of salivary As and Mn are believed to be indicative of intake from the groundwater. The clustering of salivary As and Mn in principal component analysis further indicated influence of the common exposure source. Zinc and selenium comprised a separate component presumably reflecting the local deficiencies in intakes of these essential elements from drinking water and foodstuff. Thus the study reveals that the concentration of other metals beside As must be monitored in drinking water before implementation of any policies to provide safe water to the affected communities.

Expression of Rice CYP450-Like Gene (Os08g01480) in Arabidopsis Modulates Regulatory Network Leading to Heavy Metal and Other Abiotic Stress Tolerance

Heavy metal (HM) toxicity has become a grave problem in the world since it leads to hazardous effects on living organisms. Transcriptomic/proteomic studies in plants have identified a large number of metal-responsive gene families. Of these, cytochrome-P450 (CYPs) family members are composed of enzymes carrying out detoxification of exogenous molecules. Here, we report a CYP-like protein encoded by Os08g01480 locus in rice that helps the plant to combat HM and other abiotic stresses. To functionally characterize CYP-like gene, cDNA and promoter were isolated from rice to develop Arabidopsis transgenic lines. Heterologous expression of Os08g01480 in Arabidopsis provided significant tolerance towards abiotic stresses. In silico analysis reveals that Os08g01480 might help plants to combat environmental stress via modulating auxin metabolism. Transgenic lines expressing reporter gene under control of Os08g01480 promoter demonstrated differential promoter activity in different tissues during environmental stresses. These studies indicated that differential expression of Os08g01480 might be modulating response of plants towards environmental stresses as well as in different developmental stages.

A critical review of arsenic exposures for Bangladeshi adults

Groundwater, the most important source of water for drinking, cooking, and irrigation in Bangladesh, is a significant contributor to the daily human intake of arsenic. Other arsenic intake pathways, established as relevant for Bangladeshi adults through this review, include consumption of contaminated edible plant parts and animal-origin food, inhalation of contaminated air, soil ingestion, betel quid chewing, and tobacco smoking. This review qualifies and quantifies these arsenic intake pathways through analysis of the range of arsenic levels observed in different food types, water, soil, and air in Bangladesh, and highlights the contributions of dietary intake variation and cooking method in influencing arsenic exposures. This study also highlights the potential of desirable dietary patterns and intakes in increasing arsenic exposure which is relevant to Bangladesh where nutritional deficiencies and lower-than-desirable dietary intakes continue to be a major concern.

Estimation of arsenic intake from drinking water and food (raw and cooked) in a rural village of northern Chile. Urine as a biomarker of recent exposure

The aim of this study was to estimate both the contribution of drinking water and food (raw and cooked) to the total (t-As) and inorganic (i-As) arsenic intake and the exposure of inhabitants of Socaire, a rural village in Chile´s Antofagasta Region, by using urine as biomarker. The i-As intake from food and water was estimated using samples collected between November 2008 and September 2009. A 24-hour dietary recall questionnaire was given to 20 participants. Drinking water, food (raw and cooked) and urine samples were collected directly from the homes where the interviewees lived. The percentage of i-As/t-As in the drinking water that contributed to the total intake was variable (26.8-92.9). Cereals and vegetables are the food groups that contain higher concentrations of i-As. All of the participants interviewed exceeded the reference intake FAO/OMS (149.8 µg∙i-As·day⁻¹) by approximately nine times. The concentration of t-As in urine in each individual ranged from 78 to 459 ng·mL⁻¹. Estimated As intake from drinking water and food was not associated with total urinary As concentration. The results show that both drinking water and food substantially contribute to i-As intake and an increased exposure risk to adult residents in contaminated areas.

Arsenic toxicity in rice with special reference to speciation in Indian grain and its implication on human health

BACKGROUND

Rice is a potentially important route of human exposure to arsenic, especially in populations with rice-based diets. However, arsenic toxicity varies greatly with species. The initial purpose of the present study was to evaluate arsenic speciation in rice.

RESULTS

It appeared very clear from the present study that inorganic arsenic shared maximum arsenic load in rice straw while in grains it is considerably low. As species recovered from rice grain and straw are principally As(III) and As(V) with a small amount of dimethylarsenic acid (DMA) and almost non-detectable monomethylarsonic acid (MMA) and arsenobetain (AsB). Discussion of the health risk of As in rice has largely been based on its inorganic arsenic content because these species have generally been considered to be more toxic than MMA and DMA and can be directly compared to As in drinking water, assuming equal bioavailability of inorganic As in the rice matrix and in water. The maximum dietary risk of exposure to inorganic arsenic through transplanted boro paddy in the present experiment was calculated to be almost 1706% of the provisional tolerable weekly intake for an adult of 60 kg body weight.

CONCLUSION

As species recovered from boro rice grain and straw are principally As(III) and As(V) with a small amount of DMA and almost non-detectable MMA and AsB. Reductions in total As load through organic amendments in boro rice grain and straw samples were manifested predominately through reduced accumulations of inorganic As species [As(III) and As(V)], between which As(V) accounted for the larger share.

Arsenic contamination, consequences and remediation techniques: a review

The exposure to low or high concentrations of arsenic (As), either due to the direct consumption of As contaminated drinking water, or indirectly through daily intake of As contaminated food may be fatal to the human health. Arsenic contamination in drinking water threatens more than 150 millions peoples all over the world. Around 110 millions of those peoples live in 10 countries in South and South-East Asia: Bangladesh, Cambodia, China, India, Laos, Myanmar, Nepal, Pakistan, Taiwan and Vietnam. Therefore, treatment of As contaminated water and soil could be the only effective option to minimize the health hazard. Therefore, keeping in view the above facts, an attempt has been made in this paper to review As contamination, its effect on human health and various conventional and advance technologies which are being used for the removal of As from soil and water.

Statistical analysis of causes of death (2005-2010) in villages of Simav Plain, Turkey, with high arsenic levels in drinking water supplies

The purpose of this research was to compare the causes of death in 5 villages situated in Simav Plain, Turkey, during 2005-2010 where different arsenic levels were detected in drinking water supplies. Since groundwater in Simav Plain had arsenic concentrations that ranged between 7.1 and 833.9 ppb, a two-phase research was formulated. In the first phase, public health surveys were conducted with 1,003 villagers to determine the distribution of diseases. In the second phase, verbal autopsy surveys and official death records were used to investigate the causes of death. In total, 402 death cases were found in the study area where cardiovascular system diseases (44%) and cancers (15.2%) were major causes. Cancers of lung (44.3%), prostate (9.8%), colon (9.8%), and stomach (8.2%) were comparably higher in villages with high arsenic levels in drinking water supplies. Furthermore, the majority of cases of liver, bladder, and stomach cancers were observed in villages with high arsenic levels.

Pollution status of Pakistan: a retrospective review on heavy metal contamination of water, soil, and vegetables

Trace heavy metals, such as arsenic, cadmium, lead, chromium, nickel, and mercury, are important environmental pollutants, particularly in areas with high anthropogenic pressure. In addition to these metals, copper, manganese, iron, and zinc are also important trace micronutrients. The presence of trace heavy metals in the atmosphere, soil, and water can cause serious problems to all organisms, and the ubiquitous bioavailability of these heavy metal can result in bioaccumulation in the food chain which especially can be highly dangerous to human health. This study reviews the heavy metal contamination in several areas of Pakistan over the past few years, particularly to assess the heavy metal contamination in water (ground water, surface water, and waste water), soil, sediments, particulate matter, and vegetables. The listed contaminations affect the drinking water quality, ecological environment, and food chain. Moreover, the toxicity induced by contaminated water, soil, and vegetables poses serious threat to human health.

Heterologous expression of Ceratophyllum demersum phytochelatin synthase, CdPCS1, in rice leads to lower arsenic accumulation in grain

Recent studies have identified rice (Oryza sativa) as a major dietary source of inorganic arsenic (As) and poses a significant human health risk. The predominant model for plant detoxification of heavy metals is complexation of heavy metals with phytochelatins (PCs), synthesized non-translationally by PC synthase (PCS) and compartmentalized in vacuoles. In this study, in order to restrict As in the rice roots as a detoxification mechanism, a transgenic approach has been followed through expression of phytochelatin synthase, CdPCS1, from Ceratophyllum demersum, an aquatic As-accumulator plant. CdPCS1 expressing rice transgenic lines showed marked increase in PCS activity and enhanced synthesis of PCs in comparison to non-transgenic plant. Transgenic lines showed enhanced accumulation of As in root and shoot. This enhanced metal accumulation potential of transgenic lines was positively correlated to the content of PCs, which also increased several-fold higher in transgenic lines. However, all the transgenic lines accumulated significantly lower As in grain and husk in comparison to non-transgenic plant. The higher level of PCs in transgenic plants relative to non-transgenic presumably allowed sequestering and detoxification of higher amounts of As in roots and shoots, thereby restricting its accumulation in grain.

Seasonal perspective of dietary arsenic consumption and urine arsenic in an endemic population

Exposure to arsenic in arsenic endemic areas is most remarkable environmental health challenges. Although effects of arsenic contamination are well established, reports are unavailable on probable seasonal variation due to changes of food habit depending on winter and summer seasons, especially for endemic regions of Nadia district, West Bengal. Complete 24-h diets, drinking-cooking water, first morning voided urine samples, and diet history were analyzed on 25 volunteers in arsenic endemic Chakdah block of Nadia district, once in summer followed by once in winter from the same participants. Results depicted no seasonal variation of body weight and body mass index. Arsenic concentration of source drinking and cooking water decreased (p = 0.04) from 26 μg L(-1) in summer to 6 μg L(-1) in winter season. We recorded a seasonal decrease of water intake in male (3.8 and 2.5 L day (-1)) and female (2.6 and 1.2 L day(-1)) participants from summer to winter. Arsenic intake through drinking water decreased (p = 0.04) in winter (29 μg day(-1)) than in summer (100 μg day(-1)), and urinary arsenic concentration decreased (p = 0.018) in winter (41 μg L(-1)) than in summer (69 μg L(-1)). Dietary arsenic intake remained unchanged (p = 0.24) over the seasons. Hence, we can infer that human health risk assessment from arsenic needs an insight over temporal scale.

Arsenic speciation in Australian-grown and imported rice on sale in Australia: implications for human health risk

Rice is an important route of arsenic (As) exposure to humans, especially populations with rice-based diets. Human health risk of As varies greatly with rice variety and country of origin. The purpose of the present study was to determine total and speciated As in Australian-grown and imported rice on sale in Australia to assess their health risk to consumers. The total As (tAs) concentrations in Australian-grown organic brown, medium grain brown, and organic white rice were 438±23, 287±03, and 283±18 μg kg(-1) dry weight (d wt), respectively. In Bangladeshi, Indian, Pakistani, and Thai rice imported and on sale in Australia, tAs concentrations were 56±05, 92±10, 82±06 and 172±24 μg kg(-1), respectively. Asian rice contained mainly inorganic As (iAs; 86-99%), whereas 18-26% of the tAs in Australian-grown rice was dimethylarsinic acid (DMA). Relatively higher concentrations of tAs in Australian-grown rice than that in imported rice of Asian origin suggest that Australian-grown rice may be a health risk for the consumers. It was estimated that Australian-grown organic brown rice can contribute up to 98% of the FAO/WHO recommended maximum tolerable daily intake limit of iAs (2.1 μg kg(-1) body wt day(-1)) for Asian immigrants. However, other Australian consumers including European immigrants are unlikely to be at risk to As from rice diets due to their lower rice consumption rates than that of Asian immigrants. The risk assessment showed that imported rice on sale in Australia was likely to pose a lower health risk to consumers than Australian-grown rice.

Speciation of arsenic in saliva samples from a population of West Bengal, India

Saliva, an easily accessible biofluid, is validated as biomarker of arsenic (As) exposure in several villages of West Bengal, India. Pentavalent arsenic [As(V)] was found to be the predominant species in saliva, with the amount of inorganic As [As(V) and trivalent form, As(III)] being more than half of the total As in the samples. Significant association was found between total daily ingestion of As and As(V) (r = 0.59; p = 0.000), As(III) (r = 0.60; p = 0.000), dimethylarsinous acid (DMA(V)) (r = 0.40; p = 0.000), and monomethylarsonous acid (MMA(V)) (r = 0.44; p = 0.000), implying that these species have mainly been derived from the methylation of the inorganic As in the water that study participants drank and the food they ate. Analysis of confounding effects of age, sex, smoking, body mass index and the prevalence of skin lesion suggests that women and controls with no skin lesion had a higher capacity to methylate the ingested As compared to the rest of the population. Thus, our study demonstrates that As species in saliva can be an useful tool to predict the individual susceptibility where higher As exposure and a lower methylation capacity are implicated in the development of As-induced health effects.

Enhanced Photosynthesis and Carbon Metabolism Favor Arsenic Tolerance in Artemisia annua, a Medicinal Plant as Revealed by Homology-Based Proteomics

This paper provides the first proteomic evidence of arsenic (As) tolerance and interactive regulatory network between primary and secondary metabolism in the medicinal plant, Artemisia annua. While chlorophyll fluorescence and photosynthetic rate depicted mild inhibition, there was a significant enhancement in PSI activity, whole chain, ATP, and NADPH contents in 100 μM As treatments compared to the control plants. However, a decrease in the above variables was recorded under 150 μM treatments. Proteomic decoding of the survival strategy of A. annua under As stress using 2-DE followed by MALDI-MS/MS revealed a total of 46 differentially expressed protein spots. In contrast to other plants where As inhibits photosynthesis, A. annua showed appreciable photosynthetic CO₂ assimilation and allocation of carbon resources at 100 μM As concentration. While an increased accumulation of ATP synthase, ferredoxin-NADP(H) oxidoreductase, and FeS-rieske proteins supported the operation of cyclic electron transport, mdr ABC transporter protein and pcs gene might be involved in As detoxification. The most interesting observation was an increased accumulation of LEAFY like novel protein conceivably responsible for an early onset of flowering in A. annua under As stress. This study not only affirmed the role of energy metabolism proteins but also identified potential candidates responsible for As tolerance in plants.

Food safety and bioavailability evaluations of four vegetables grown in the highly arsenic-contaminated soils on the Guandu Plain of northern Taiwan

Arsenic contamination in a large area of agricultural fields on the Guandu Plain of northern Taiwan was confirmed in a survey conducted in 2006, but research concerning the relationship between bioavailable As concentrations in contaminated soils and crop production in Taiwan is not available. Pot experiments were conducted to examine the growth and accumulation of As in four vegetable crops grown in As-contaminated soils and to assess As intake through consumption. The phytotoxic effects of As in soils were not shown in the pot experiments in which vegetable crops were grown in soils contaminated with different As levels in situ collected from Guandu Plain (120–460 mg/kg) or artificially spiked As-contaminated soils (50–170 mg/kg). Experimental results showed that the bioavailable As extracted with 5 M NaHCO₃ from soils can be used to estimate As concentrations in vegetables. The As concentrations in the vegetables were compared with data shown in the literature and As limits calculated from drinking water standards and the provisional tolerance weekly intake (PTWI) of inorganic As established by the Food and Agriculture Organization of the United Nations/World Health Organization (FAO/WHO). Although the As levels in the vegetables were not high and the bioavailability of As in the soils was quite low, long-term consumption may result in higher As intake in the human body.

Fluoride and arsenic exposure through water and grain crops in Nagarparkar, Pakistan

The aim of present study was to simultaneously estimate the arsenic (As) and fluoride (F(-)) concentrations in irrigated surface water, soil and grain crops of Nagarparkar, Pakistan during 2010-2012. The As and F(-) were analyzed by hydride generation atomic absorption spectrometer and ion selective electrode, respectively. Total arsenic (As(T)) and F(-) in irrigated surface water samples were found in the range of 360-683 μg L(-1) and 18.5-35.4 mg L(-1), respectively. While As(T) and F(-) concentrations in agriculture soil samples were observed in the range of 110-266 and 125-566 mg kg(-1), respectively. The water extractable As and F(-) were found 3-4% of total concentration of these in soils. The As(T) concentration was higher in kidney been (KB) as compared to pearl millet (PM) and green gram (GG), whereas GG had higher F(-) levels as compared to other two grain crops (p<0.05). The KB samples grown in nine sites shows BCF of As in the range of 0.018-0.038. The GG has higher BCF of F(-) as compared to KB and PM (p<0.05) grown in all sites. The exposure dose and risk factor of As and F(-) were obtained by estimated daily intake (EDI) and hazardous index (HI). It was found that all understudy age groups were at the severe risk of arsenicosis and fluorosis, but the severity is higher in younger age group (7-15 years) as compared to elder groups (p<0.05).

High arsenic in rice is associated with elevated genotoxic effects in humans

Arsenic in drinking water may cause major deleterious health impacts including death. Although arsenic in rice has recently been demonstrated to be a potential exposure route for humans, there has been to date no direct evidence for the impact of such exposure on human health. Here we show for the first time, through a cohort study in West Bengal, India, involving over 400 human subjects not otherwise significantly exposed to arsenic through drinking water, elevated genotoxic effects, as measured by micronuclei (MN) in urothelial cells, associated with the staple consumption of cooked rice with >200 μg/kg arsenic. Further work is required to determine the applicability to populations with different dietary and genetic characteristics, but with over 3 billion people in the world consuming rice as a staple food and several percent of this rice containing such elevated arsenic concentrations, this study raises considerable concerns over the threat to human health.

Dietary arsenic exposure with low level of arsenic in drinking water and biomarker: a study in West Bengal

The authors investigated association of arsenic intake through water and diet and arsenic level in urine in people living in arsenic endemic region in West Bengal supplied with arsenic-safe water (<50 μg L(-1)). Out of 94 (Group-1A) study participants using water with arsenic level <50 μg L(-1), 72 participants (Group-1B) were taking water with arsenic level <10 μg L(-1). Multiple regressions analysis conducted on the Group-1A participants showed that daily arsenic dose from water and diet were found to be significantly positively associated with urinary arsenic level. However, daily arsenic dose from diet was found to be significantly positively associated with urinary arsenic level in Group-1B participants only, but no significant association was found with arsenic dose from water in this group. In a separate analysis, out of 68 participants with arsenic exposure through diet only, urinary arsenic concentration was found to correlate positively (r = 0.573) with dietary arsenic in 45 participants with skin lesion while this correlation was insignificant (r = 0.007) in 23 participants without skin lesion. Our study suggested that dietary arsenic intake was a potential pathway of arsenic exposure even where arsenic intake through water was reduced significantly in arsenic endemic region in West Bengal. Observation of variation in urinary arsenic excretion in arsenic-exposed subjects with and without skin lesion needed further study.

Dietary arsenic consumption and urine arsenic in an endemic population: response to improvement of drinking water quality in a 2-year consecutive study

We assessed the association between arsenic intake through water and diet, and arsenic levels in first morning-void urine under variable conditions of water contamination. This was done in a 2-year consecutive study in an endemic population. Exposure of arsenic through water and diet was assessed for participants using arsenic-contaminated water (≥50 μg L(-1)) in a first year (group I) and for participants using water lower in arsenic (<50 μg L(-1)) in the next year (group II). Participants with and without arsenical skin lesions were considered in the statistical analysis. Median dose of arsenic intake through drinking water in groups I and II males was 7.44 and 0.85 μg kg body wt.(-1) day(-1) (p <0.0001). In females, it was 5.3 and 0.63 μg kg body wt.(-1) day(-1) (p <0.0001) for groups I and II, respectively. Arsenic dose through diet was 3.3 and 2.6 μg kg body wt.(-1) day(-1) (p = 0.088) in males and 2.6 and 1.9 μg kg body wt.(-1) day(-1) (p = 0.0081) in females. Median arsenic levels in urine of groups I and II males were 124 and 61 μg L(-1) (p = 0.052) and in females 130 and 52 μg L(-1) (p = 0.0001), respectively. When arsenic levels in the water were reduced to below 50 μg L(-1) (Indian permissible limit), total arsenic intake and arsenic intake through the water significantly decreased, but arsenic uptake through the diet was found to be not significantly affected. Moreover, it was found that drinking water mainly contributed to variations in urine arsenic concentrations. However, differences between male and female participants also indicate that not only arsenic uptake, but also many physiological factors affect arsenic behavior in the body and its excretion. As total median arsenic exposure still often exceeded 3.0 μg kg body wt.(-1) day(-1) (the permissible lower limit established by the Joint Expert Committee on Food Additives) after installation of the drinking water filters, it can be concluded that supplying the filtered water only may not be sufficient to minimize arsenic availability for an already endemic population.

Arsenic concentration in rice, fish, meat and vegetables in Cambodia: a preliminary risk assessment

To assess arsenic contaminations and its possible adverse health effects, food samples were collected from Kandal, Kratie and Kampong Cham in Cambodia. The highest and the lowest concentrations were observed in fish (mean 2,832 ng g(-1), ww) collected from Kandal province and cattle stomach (1.86 ± 1.10 ng g(-1), ww) collected from Kratie, respectively. The daily intake of arsenic via food consumption was 604, 9.70 and 136 μg day(-1) in Kandal, Kratie and Kampong Cham, respectively. The arsenic dietary intake in Kandal ranked No. 1 among all the 17 compared countries or regions. Fish consumption contributed the greatest proportion of total arsenic daily intake in Kandal (about 63.0 %) and Kampong Cham (about 69.8 %). It is revealed to be a much more important exposure pathway than drinking water for residents in Kampong Cham. The results of risk assessment suggested that the residents in Cambodia, particularly for people in Kandal province, suffer high public health risks due to consuming arsenic-contaminated food.

Arsenic contamination in groundwater and its effects on adolescent intelligence and social competence in Bangladesh with special reference to daily drinking/cooking water intake

OBJECTIVE

The present study aims to investigate the relationship between arsenic (As) exposure and intelligence quotient (IQ) or social competence (SC) of Bangladeshi adolescents (aged 14 or 15 years) in Sonargaon thana.

METHODS

Information about socioeconomic status (SES) was collected as confounding factors. To evaluate the relative contribution of As sources to total As intake, the As concentrations in urine and drinking/cooking water, and the amount of water added in cooking, were assessed on site using a food frequency questionnaire (FFQ).

RESULTS

The results confirmed that As exposure was essential to lower adolescent IQ or SC because they were negatively associated with As exposure after controlling for SES (particularly household income). Except for cooking water, the amount of drinking water varied with season and appeared to be the major As source because the As concentration in water was generally correlated with the As concentration in urine, and they were related to lower IQ or SC (even after controlling for SES). The FFQ survey revealed that rice was consumed the most frequently (more than once daily), followed by daal (bean) soup and nonleafy vegetables, but fish, meat, and eggs were consumed approximately once a week. Water intake per meal from cooked rice was estimated to be 616 mL/person, followed by bean soup (258 mL/person) and cooked vegetables (82 mL/person).

CONCLUSIONS

Our results suggest that water used for cooking might be an important source of As, and the cooking process can affect the amount of As in cooked food.

Water consumption patterns and factors contributing to water consumption in arsenic affected population of rural West Bengal, India

A direct water intake study was conducted for one year, involving 423 individuals from three arsenic (As) affected villages of West Bengal, India. Average direct water intake per person and per unit body weight was found to be 3.12±1.17 L/day and 78.07±47.08 mL/kg/day (± SD), respectively. Average direct water intakes for adult males, adult females and children (age <15 years) were 3.95, 3.03 and 2.14 L/day, respectively. Significant sex differentials were observed between ages 16-55 years. For all participants, a sharp increase in water intake up to 15 years of age was observed followed by a plateau at a higher intake level. Significant monthly, seasonal, regional, and occupational variability was also observed. Another study involving 413 subjects determined the amount of indirect water intake. Average indirect water intake per person was 1.80±0.64 L/day; for adult males, adult females and children, intake was 2.15, 1.81, and 1.10 L/day, respectively. Average total (direct + indirect) water intake was 4.92 L/person/day; for adult males, adult females and children, total intake was 6.10, 4.84, and 3.24 L/person/day, respectively. The overall contribution of indirect water intake to total water consumption was 36.6% for all participants. This study additionally elucidated several factors that contribute to variable water intake, which can lead to better risk characterization of subpopulations and water contaminant ingestion. The study reveals that the water intake rates in the three studied populations in West Bengal are greater than the assumed water intake rates utilized by the World Health Organization (WHO) in the establishment of drinking water quality guidelines; therefore, these assumed intake values may be inappropriate for the study population as well as similar ones.

Impact of arsenic toxicity on black gram and its amelioration using phosphate

The toxicity of arsenic in soil and ground water is one of the most important environmental problems particularly in South-East Asia. Arsenic-polluted irrigation water creates hazard in soil environment and also in crop quality. In the present study, response of black gram (Vigna mungo L.) to arsenic with or without phosphate application was investigated. Arsenic-treated plants showed reduction in their growth and pigment content. Arsenic significantly enhanced lipid peroxidation, electrolyte leakage, and level of proline showing oxidative stress. Arsenic toxicity was associated with an increase in the activities of antioxidative enzymes like superoxide dismutase, peroxidase, and ascorbate peroxidase whereas catalase activity decreased at higher arsenic dose. Joint application of phosphate with arsenic resulted in significant alterations in most of the parameters tested under the purview of arsenic treatment alone which lead to better growth in black gram.

Home gardening near a mining site in an arsenic-endemic region of Arizona: assessing arsenic exposure dose and risk via ingestion of home garden vegetables, soils, and water

The human-health risk posed by gardening near a legacy mine and smelter in an arsenic-endemic region of Arizona was characterized in this study. Residential soils were used in a greenhouse study to grow common vegetables, and local residents, after training, collected soil, water, and vegetables samples from their home gardens. Concentrations of arsenic measured in water, soil, and vegetable samples were used in conjunction with reported US intake rates to calculate the daily dose, Incremental Excess Lifetime Cancer Risk (IELCR), and Hazard Quotient for arsenic. Relative arsenic intake dose decreased in order: water>garden soils>homegrown vegetables, and on average, each accounted for 77, 16, and 7% of a residential gardener's daily arsenic intake dose. The IELCR ranges for vegetables, garden soils, and water were 10(-8) to 10(-4), 10(-6) to 10(-4), and 10(-5) to 10(-2), respectively. All vegetables (greenhouse and home garden) were grouped by scientific family, and the risk posed decreased as: Asteraceae≫Fabaceae>Amaranthaceae>Liliaceae>Brassicaceae>Solanaceae≫Cucurbitaceae. Correlations observed between concentrations of arsenic in vegetables and soils were used to estimate a maximum allowable level of arsenic in soil to limit the excess cancer risk to 10(-6). The estimated values are 1.56 mg kg(-1), 5.39 mg kg(-1), 11.6 mg kg(-1) and 12.4 mg kg(-1) for the Asteraceae, Brassicaceae, Fabaceae, and Amaranthaceae families, respectively. It is recommended that home gardeners: sample their private wells annually, test their soils prior to gardening, and, if necessary, modify their gardening behavior to reduce incidental soil ingestion. This study highlights the importance of site-specific risk assessment, and the need for species-specific planting guidelines for communities.

Total and inorganic arsenic contents in some edible zingiberaceous rhizomes in Thailand

The arsenic accumulation in rhizomes of Zingiberaceous plants was determined by atomic absorption spectrometry interfaced with hydride generation system (HG-AAS). The raw herbal materials, rhizomes, were collected from different regions of Thailand between December 2011 and January 2012. Six well-known Zingiberaceous plants, 16 samples from each and a total of 96 samples, were analyzed Alpinia galanga (Khaa), Boesenbergia rotunda (Kra-chaai), Curcuma longa (Khamin-chan), Curcuma zedoaria (Khamin-oi), Zingiber cassumunar (Plai) and Zingiber officinale (Ginger). Concentrations of total arsenic based on dry weight were 92.4 ± 9.2, 103.5 ± 20.8, 61.7 ± 12.5, 89.8 ± 17.5, 106.7 ± 19.5 and 69.3 ± 11.8 ng/g, respectively and inorganic arsenic were 48.8 ± 7.0, 66.3 ± 12.7, 25.5 ± 5.0, 38.7 ± 4.7, 71.2 ± 11.6, and 38.5 ± 5.5 ng/g, respectively. Among these, Plai and Kra-chaai exhibited the highest levels of total arsenic and inorganic arsenic accumulation that remind consumers to be aware of excess consuming of these rhizomes. On the contrary, the lowest value found in Khamin-chan indicating natural dietary supplements and herbal medicines comprising Kamin-chan are safe from arsenic poison. All investigated amounts of total and inorganic arsenic were much lower than limits recommended by Thai Food and Drug Administration.

Is saliva a potential biomarker of arsenic exposure? A case-control study in West Bengal, India

Saliva is a biological fluid that has not been used extensively as a biomonitoring tool in epidemiological studies. This study presents the arsenic (As) concentrations in saliva and urine samples collected from populations of West Bengal, India who had been previously exposed to high As levels in their drinking water. We found a significant (p < 0.05) association between the Log transformed Daily Ingestion of As (μg day(-1)) and the As concentration in saliva (r = 0.68). Additionally, As concentration of saliva and urine also had a significant positive correlation (r = 0.60, p < 0.05). Male participants, smokers, and cases of skin lesion were independently and significantly associated with an increase in salivary As. Thus our findings show that saliva is a useful biomarker of As exposure in the study population. The study also advocates that measurement of the forms of As in saliva may additionally provide insight into the internal dose and any individual differences in susceptibility to As exposure.

Expression of a rice Lambda class of glutathione S-transferase, OsGSTL2, in Arabidopsis provides tolerance to heavy metal and other abiotic stresses

Global industrial growth has contaminated the soil and water with many hazardous compounds, including heavy metals. These heavy metals are not only toxic to plants but also cause severe human health hazards when leach out into food chain. One of the approaches employed for the decontamination of environment includes identification and overexpression of genes involved in the detoxification mechanism of plants. Glutathione S-transferases (GSTs) are a superfamily of enzymes, principally known for their role in detoxification reactions. Different classes of GSTs have been used to develop plants with improved detoxification mechanism, but not much information is available for Lambda class of GSTs. Here, we studied expression of OsGSTLs in different rice genotypes under arsenic stress. The study suggests differential expression of these genes in arsenic sensitive and tolerant genotypes. Further, the role of one member of Lambda class OsGSTL2 was studied by expressing in heterologous system, Arabidopsis. Transgenic lines developed were analysed for their response to different abiotic stresses including heavy metals. Analysis suggests that OsGSTL2 provides tolerance for heavy metals and other abiotic stresses like cold, osmotic stress and salt. We conclude that OsGSTLs can be utilized for developing plant varieties tolerant to different abiotic stresses including heavy metals.

Arsenic contamination: a potential hazard to the affected areas of West Bengal, India

Arsenic contamination in groundwater is becoming more and more a worldwide problem. Nearing 50 million of people are at health risk from arsenic contamination at Ganga-Meghna-Bramhaputra basin. The experimental results of the five blocks under Malda district of West Bengal, India, showed that the arsenic concentration in groundwater (0.41-1.01 mg/l) was higher than the permissible limit for drinking water (0.01 mg/l) (WHO) and FAO (Food and Agriculture Organization) permissible limit for irrigation water (0.10 mg/l). The soil arsenic level (13.12 mg/kg) crossed the global average (10.0 mg/kg), but within the maximum acceptable limit for agricultural soil (20.0 mg/kg) recommended by the European Union. The total arsenic concentration on food crops varied from 0.000 to 1.464 mg/kg of dry weight. The highest mean arsenic concentration was found in potato (0.456 mg/kg), followed by rice grain (0.429 mg/kg). The total mean arsenic content (milligrams per kg dry weight) in cereals ranged from 0.121 to 0.429 mg/kg, in pulses and oilseeds ranged from 0.076 to 0.168 mg/kg, in tuber crops ranged from 0.243 to 0.456 mg/kg, in spices ranged from 0.031 to 0.175 mg/kg, in fruits ranged from 0.021 to 0.145 mg/kg and in vegetables ranged from 0.032 to 0.411 mg/kg, respectively. Hence, arsenic accumulation in cereals, pulses, oilseed, vegetables, spices, cole crop and fruits crop might not be safe in future without any sustainable mitigation strategies to avert the potential arsenic toxicity on the human health in the contaminated areas.

Risk of arsenic exposure from drinking water and dietary components: implications for risk management in rural Bengal

This study investigates the risk of arsenic (As) exposure to the communities in rural Bengal, even when they have been supplied with As safe drinking water. The estimates of exposure via dietary and drinking water routes show that, when people are consuming water with an As concentration of less than 10 μg L(-1), the total daily intake of inorganic As (TDI-iAs) exceeds the previous provisional tolerable daily intake (PTDI) value of 2.1 μg day(-1) kg(-1) BW, recommended by the World Health Organization (WHO) in 35% of the cases due to consumption of rice. When the level of As concentration in drinking water is above 10 μg L(-1), the TDI-iAs exceeds the previous PTDI for all the participants. These results imply that, when rice consumption is a significant contributor to the TDI-iAs, supplying water with an As concentration at the current national drinking water standard for India and Bangladesh would place many people above the safety threshold of PTDI. We also found that the consumption of vegetables in rural Bengal does not pose a significant health threat to the population independently. This study suggests that any effort to mitigate the As exposure of the villagers in Bengal must consider the risk of As exposure from rice consumption together with drinking water.

Evaluation of dietary arsenic exposure and its biomarkers: a case study of West Bengal, India

Few reports are available that characterize daily arsenic exposure through water and diet among people living in groundwater-contaminated regions and correlate it with biomarkers. The present study describes the total individual arsenic exposure and arsenic level in urine and hair of such an arsenic-exposed population in West Bengal. Demographic characteristics and the total daily arsenic intake through water and diet were determined in 167 (Group-1 participants selected from arsenic endemic region) and 69 (Group-2 participants selected from arsenic non-endemic region) in West Bengal. Out of 167 Group-1 participants 78 (Group-1A) had arsenical skin lesions while 89 Group-1B) had no such lesion. Arsenic level in water samples as well as diet, urine and hair samples, collected from all the individual participants, were estimated. The mean value of estimated total arsenic content from water and diet was 349 (range: 20-1615) μg/day in 167 (Group-1) participants living in As endemic region [As in water: mean value 54 (range:BDL-326) μg/L] and 36 (range:12-120) μg/day in 69 (Group-2) participants living in As non-endemic region (As in water: below detection level (BDL), < 0.3 μg/L). Estimated mean arsenic level in urine in these two groups of participants was 116 (range: 6-526) μg/L and 17 (range: BDL-37) μg/L and in hair was 1.0 (range: 0.22-3.98) mg/Kg and 0.16 (range: 0.06-0.37) mg/Kg, respectively. Multiple regressions analysis in Group-1 participants showed that total arsenic intake was associated significantly with urinary and hair arsenic level. The estimated regression coefficient was 0.0022 (95% confidence interval, C.I: 0.0016, 0.0028; P < 0.001) and 0.0024 (95% C.I: 0.0021, 0.003; P < 0.001), respectively. In sub group analysis, higher median urinary arsenic value relative to arsenic intake through water and diet was observed in 78 Group-1A subjects with skin lesion compared to urinary arsenic value in 89 Group-1B subjects without skin lesions, though there was a marginal difference of median total arsenic intake in these two groups. This study showed that significant elevation of arsenic level in urine and hair was associated with elevated arsenic intake through water and diet in people living in arsenic endemic region (Group-1), while these values were low in people living in non-endemic region (Group-2). Those with skin lesions were found to have higher arsenic in urine and hair compared to those without skin lesion with similar arsenic intake through water and diet.

Arsenic contaminated groundwater and its treatment options in Bangladesh

Arsenic (As) causes health concerns due to its significant toxicity and worldwide presence in drinking water and groundwater. The major sources of As pollution may be natural process such as dissolution of As-containing minerals and anthropogenic activities such as percolation of water from mines, etc. The maximum contaminant level for total As in potable water has been established as 10 µg/L. Among the countries facing As contamination problems, Bangladesh is the most affected. Up to 77 million people in Bangladesh have been exposed to toxic levels of arsenic from drinking water. Therefore, it has become an urgent need to provide As-free drinking water in rural households throughout Bangladesh. This paper provides a comprehensive overview on the recent data on arsenic contamination status, its sources and reasons of mobilization and the exposure pathways in Bangladesh. Very little literature has focused on the removal of As from groundwaters in developing countries and thus this paper aims to review the As removal technologies and be a useful resource for researchers or policy makers to help identify and investigate useful treatment options. While a number of technological developments in arsenic removal have taken place, we must consider variations in sources and quality characteristics of As polluted water and differences in the socio-economic and literacy conditions of people, and then aim at improving effectiveness in arsenic removal, reducing the cost of the system, making the technology user friendly, overcoming maintenance problems and resolving sludge management issues.

Arsenic residue in the products and by-products of chicken and ducks

Arsenicosis caused due to drinking of arsenic contaminated ground water is a major environmental health hazard throughout the world. We evaluated the ecotoxicological effect of arsenic on chicken and duck in an arsenic endemic zone. The concentration of arsenic was higher in chicken and duck feed and their by-products than that in the respective samples of control area. Arsenic concentration in the eggs of both chicken and duck was higher than that in the respective samples of control area. Thus, we concluded that arsenic enters into food chain through the intake of contaminated eggs. Furthermore, adverse health effect of arsenic on avian population is due to the alteration in haematobiochemical indices.

Arsenic-induced health crisis in peri-urban Moyna and Ardebok villages, West Bengal, India: an exposure assessment study

Drinking of arsenic (As)-contaminated groundwater has adverse effects on health of millions of people worldwide. This study aimed to determine the degree of severity of As exposure from drinking water in peri-urban Moyna and Ardebok villages, West Bengal, India. Arsenic concentrations in hair, nail and urine samp les of the individuals were determined. Arsenical dermatosis, keratosis and melanosis were investigated through medical evaluation. We have evaluated the association between As exposure from drinking water, and keratosis and melanosis outcomes. The results showed that 82.7 % of the sampled tube wells contain As concentrations above 10 μg/L, while 57.7 % contain As concentrations above 50 μg/L. The hair, nail and urine As concentrations were positively correlated with As concentrations in drinking water. In our study population, we observed a strong association between As concentrations ranging 51-99 μg/L and keratosis and melanosis outcomes, although the probability decreases at higher concentration ranges perhaps due to switching away from the use of As-contaminated tube wells for drinking and cooking purposes. High As concentrations in hair, nail and urine were observed to be associated with the age of the study population. The level of As concentrations in hair, nail and urine samples of the study population indicated the degree of severity of As exposure in the study region.

Evaluation of health risk and arsenic levels in vegetables sold in markets of Dhaka (Bangladesh) and Salamanca (Spain) by hydride generation atomic absorption spectroscopy

The main objective of this study was to determine arsenic (As) levels in vegetables collected from the markets of Dhaka, Bangladesh and for comparison from Salamanca, Spain by HGAAS under optimal conditions, and the potential health risk from consumption of these vegetables. The mean and range of the total As concentration in the vegetables from the markets of Dhaka, Bangladesh were 114 and 1.0-293 μg/kg, respectively. Total As concentration in 77% of Bangladesh vegetables measured was higher than that recommended by the standard. The mean and range of As concentrations for vegetables grown in Spain were 65 and bdl-130 μg/kg, respectively, for Salamanca, 102 and bdl-423 μg/kg, respectively, for Almeria. The As content of the Bangladesh vegetables was approximately twofold to threefold higher than those observed for the vegetables from Almeria and Salamanca (Spain), but in some cases, were similar or less. Daily consumption of As-rich vegetables may result in an additional source of As in the diet, based on the provisional tolerable intake of As for adults recommended by WHO.

Risk from winter vegetables and pulses produced in arsenic endemic areas of Nadia District: field study comparison with market basket survey

Arsenic contaminated groundwater uses for irrigation potentially lead the incidence of arsenic into food chain. In present study we examined total arsenic concentrations in 32 types of vegetables and 7 types of pulses. Range of total arsenic concentration in edible parts of vegetables collected from grown fields was 0.114-0.910 mg/kg. Highest arsenic values were in spinach 0.910 mg/kg. Vegetable samples were grouped into leafy, non-leafy-fruity, root-tubers. 18 common types of vegetables and pulses were collected through market basket survey, total arsenic were approximately 100 mg lower than those observed for the vegetables collected from the fields.

Arsenic-induced changes in morphological, physiological, and biochemical attributes and artemisinin biosynthesis in Artemisia annua, an antimalarial plant

Present study is the first to explore physiological, biochemical and molecular changes in the medicinal plant Artemisia annua under arsenic (As) stress. A. annua grown hydroponically in a nutrient solution was spiked with increasing doses of As (0, 1,500, 3,000 and 4,500 μg l(-1)) for 7 days. Plants accumulated As in a dose dependent manner with bioconcentration factor 13.4 and translocation factor 0.97. While a similar trend of As accumulation was observed under soil culture experiments, the transfer factor went up to 2.1, depicting high efficiency of As translocation from roots to shoots by A. annua. Plants raised in 0-3,000 μg l(-1) As containing nutrient solution registered increase in root length, biomass, and carotenoid contents without any visual toxicity symptoms. A dose dependent increase in the activities of enzymes such as superoxide dismutase, ascorbate peroxidase, glutathione reductase and guaiacol peroxidase followed by a gradual decline at higher concentrations suggested their role in alleviating oxidative stress. Significant increase in the levels of thiols, GSH, and pcs gene transcript up to 3,000 μg l(-1) As attested their roles in As detoxification. Enhanced artemisinin production (an antimalarial compound) under As stress and upregulation of the transcripts (measured by RT-PCR) of the genes HMGR, FDS, ADS, and CYP71AV1 involved in artemisinin biosynthesis reaffirmed induction of artemisinin biosynthesis in A. annua under As stress. The results of the present study vividly suggested that A. annua has considerable As tolerance, and thus can be successfully cultivated in As contaminated fields.

Proteomics combines morphological, physiological and biochemical attributes to unravel the survival strategy of Anabaena sp. PCC7120 under arsenic stress

Proteomics in conjunction with morphological, physiological and biochemical variables has been employed for the first time to unravel survival strategies of the diazotrophic cyanobacterium Anabaena sp. PCC7120 under Arsenic (As) stress. Significant reduction in growth, carbon fixation, nitrogenase activity and chlorophyll content after 1 day (1d) and recovery after 15 days (15d) of As exposure indicates the acclimation of the test organism against As stress. The formation of akinete like structures is a novel observation never reported before in Anabaena sp. PCC7120. Proteomic characterization using 2-DE showed average 537, 422 and 439 spots in control, 1 and 15d treatment respectively. MALDI-TOF and LC-MS of As-treated Anabaena revealed a total of 45 differentially expressed proteins, of which 13 were novel (hypothetical) ones. Down-regulation of phosphoglycerate kinase (PGK), fructose bisphosphate aldolase II (FBA II), fructose 1,6 bisphosphatase (FBPase), transketolase (TK), and ATP synthase on day 1 and their significant recovery on the 15th day presumably maintained the glycolysis, pentose phosphate pathway (PPP) and turnover rate of Calvin cycle, hence survival of the test organism. Up-regulation of catalase (CAT), peroxiredoxin (Prx), thioredoxin (Trx) and oxidoreductase appears to protect the cells from oxidative stress. Appreciable induction in phytochelatin content (2.4 fold), GST activity (2.3 fold), and transcripts of phytochelatin synthase (5.0 fold), arsenate reductase (8.5 fold) and arsenite efflux genes - asr1102 (5.0 fold), alr1097 (4.7 fold) reiterates their role in As sequestration and shielding of the organism from As toxicity. While up-regulated metabolic and antioxidative defense proteins, phytochelatin and GST work synchronously, the ars genes play a central role in detoxification and survival of Anabaena under As stress. The proposed hypothetical model explains the interaction of metabolic proteins associated with the survival of Anabaena sp. PCC7120 under As stress.

High levels of inorganic arsenic in rice in areas where arsenic-contaminated water is used for irrigation and cooking

Rice is the staple food for the people of arsenic endemic South (S) and South-East (SE) Asian countries. In this region, arsenic contaminated groundwater has been used not only for drinking and cooking purposes but also for rice cultivation during dry season. Irrigation of arsenic-contaminated groundwater for rice cultivation has resulted high deposition of arsenic in topsoil and uptake in rice grain posing a serious threat to the sustainable agriculture in this region. In addition, cooking rice with arsenic-contaminated water also increases arsenic burden in cooked rice. Inorganic arsenic is the main species of S and SE Asian rice (80 to 91% of the total arsenic), and the concentration of this toxic species is increased in cooked rice from inorganic arsenic-rich cooking water. The people of Bangladesh and West Bengal (India), the arsenic hot spots in the world, eat an average of 450g rice a day. Therefore, in addition to drinking water, dietary intake of arsenic from rice is supposed to be another potential source of exposure, and to be a new disaster for the population of S and SE Asian countries. Arsenic speciation in raw and cooked rice, its bioavailability and the possible health hazard of inorganic arsenic in rice for the population of S and SE Asia have been discussed in this review.

Exposure to multiple metals from groundwater-a global crisis: geology, climate change, health effects, testing, and mitigation

This paper presents an overview of the global extent of naturally occurring toxic metals in groundwater. Adverse health effects attributed to the toxic metals most commonly found in groundwater are reviewed, as well as chemical, biochemical, and physiological interactions between these metals. Synergistic and antagonistic effects that have been reported between the toxic metals found in groundwater and the dietary trace elements are highlighted, and common behavioural, cultural, and dietary practices that are likely to significantly modify health risks due to use of metal-contaminated groundwater are reviewed. Methods for analytical testing of samples containing multiple metals are discussed, with special attention to analytical interferences between metals and reagents. An overview is presented of approaches to providing safe water when groundwater contains multiple metallic toxins.

Processing conditions, rice properties, health and environment

Rice is the staple food for nearly two-thirds of the world’s population. Food components and environmental load of rice depends on the rice form that is resulted by different processing conditions. Brown rice (BR), germinated brown rice (GBR) and partially-milled rice (PMR) contains more health beneficial food components compared to the well milled rice (WMR). Although the arsenic concentration in cooked rice depends on the cooking methods, parboiled rice (PBR) seems to be relatively prone to arsenic contamination compared to that of untreated rice, if contaminated water is used for parboiling and cooking. A change in consumption patterns from PBR to untreated rice (non-parboiled), and WMR to PMR or BR may conserve about 43–54 million tons of rice and reduce the risk from arsenic contamination in the arsenic prone area. This study also reveals that a change in rice consumption patterns not only supply more food components but also reduces environmental loads. A switch in production and consumption patterns would improve food security where food grains are scarce, and provide more health beneficial food components, may prevent some diseases and ease the burden on the Earth. However, motivation and awareness of the environment and health, and even a nominal incentive may require for a method switching which may help in building a sustainable society.

Human exposure to arsenic through foodstuffs cultivated using arsenic contaminated groundwater in areas of West Bengal, India

The widespread incidence of chronic arsenicosis in the Bengal Delta has led to intensive research on arsenic (As) enrichment in groundwater as well as accumulation in foodstuffs, as there are potential health risks associated with exposure to As from both sources. This study deals with human As exposure through the drinking of groundwater, consumption of locally grown foodstuffs (e.g., crops and vegetables) and cooked food in Nadia district, West Bengal. Groundwater and foodstuffs were collected and analyzed with FI-HG-AAS to estimate the total As content. Urine samples collected from human subjects were analyzed to assess the As exposure. Two major crops, boro and aman rice, showed a considerable amount of As, with mean values of 194 and 156 μg kg(-1), respectively. Significant levels of As were also found in other common crops and vegetables cultivated in this area (for example, the mean As in Arum and radish was 780 and 674 μg kg(-1), respectively). Total intake of As from foodstuffs by adults (560 μg day(-1)) and children (393 μg day(-1)) in the area was found to be at alarming levels. Arsenic exposure was demonstrated by the presence of As in urine (ranging between 154 and 276 μg L(-1)), with overall As retention of 50-60 %. The results of this study further indicate the potential risk of As exposure to local inhabitants through the food chain which is associated with continuous consumption of As-contaminated foodstuffs. Therefore, more action needs to be taken to control the contamination pathways (such as the water-soil-crop system) to protect humans from continuous ingestion of As through foodstuffs.