Elsevier

Clinica Chimica Acta

Volume 455, 1 April 2016, Pages 99-101
Clinica Chimica Acta

Blood arsenic: Pan-India prevalence

https://doi.org/10.1016/j.cca.2016.02.001Get rights and content

Highlights

  • Our report is one of the few to document average serum levels of arsenic in the Indian population.

  • A pan-India cohort of both the gender from age-group of < 2 to older adults was analyzed in this study.

  • Superior analytical platform of ICP-MS has been used for the analysis.

  • Our report is one of the few to study and highlight arsenic prevalence in a pan-India level.

Abstract

Introduction

Arsenic, a well-known toxic element, has become one of the biggest causes for clinical concerns among elemental toxicities. Arsenicosis has been reported from many regions of the country, especially on exposure induced by ground water contamination. The clinical effects of chronic arsenic toxicity are generally varied and its timely diagnosis and management pose a big challenge.

Methodology

Our study reports analysis of blood arsenic levels in a pan-India cohort of 205,530 including 111,737 males and 93,793 females respectively. The cohort included all age groups from infants to old adults. Arsenic levels were analyzed using the analytical platform of ICP-MS touted to be the gold standard for elemental analysis.

Result

Blood arsenic levels of ≥ 5 μg/L were considered high in our study. The total frequency of high arsenic cases detected in the study is 1.37%. The frequency in males was 1.47% and in females it was detected to be 1.25%. Also, maximum cases of high arsenic levels were detected to be from the state of Kerala and in cities from Mumbai.

Conclusion

Very few studies have recorded the frequency of high arsenic levels in Indians as well as its average blood levels in a pan-India cohort. Our study has made a pilot attempt to highlight the same to generate awareness about this elemental menace in the Indian context.

Introduction

Elements generally occur in their natural form in the Earth's crust, some being important micronutrients while many being absolutely toxic. Arsenic is the twentieth most abundant element and the inorganic form is the most toxic in comparison to certain organic compounds like arsenobetaine and arsenocholine which is tolerated better [1], [2]. In India, cases of arsenic toxicity have been reported mainly from West Bengal and also regions around rivers like Ganga and Bramhaputra. [3]. Groundwater contamination by arsenic continues to remain the major source of exposure in the country leading to cases of chronic arsenic toxicity. Projects on groundwater testing for arsenic undertaken as a government initiative with support from UNICEF have identified many affected regions like West Bengal, Assam, and Uttar Pradesh and regions around the Ganges–Brahmaputra basin [4]. Arsenicosis affected individuals generally present with symptoms of skin lesions like pigmentation, keratosis or melanosis which could range anywhere between moderate to severe. Symptoms of early acute toxicity include muscular pain, nausea, and vomiting and rice-watery stool diarrhea. Severe toxicity is known to cause kidney failure, seizures and finally death due to shock [5].

Humans are exposed to arsenic either by ingestion, inhalation or through skin exposure. Ingestion apart from contaminated water can be from food grown using pesticides containing arsenic or in soil contaminated by the same; while inhalation can be through contaminated fumes or mist. Arsenic was also widely used for treatment of conditions like asthma and malignancies using Fowler's solution and also for psoriasis, syphilis, etc. parenterally [6]. The ingested as well as inhaled arsenic is absorbed through the gastrointestinal tract and lungs to enter the blood stream by binding to the red blood cells through which it is then distributed to other major organs like kidneys and liver. This has been shown by labeled arsenic studies carried out in different mammalian tissues [7]. The liver is then involved in detoxification of the same, and roughly 70% of the ingested arsenic is excreted through urine [5].

Treatment modalities for arsenicosis are not much and as such there are no effective medications available for treatment, post-complications develop. Diagnosis of the condition is done by assessment of the skin lesions i.e. melanosis, keratomalacia as well as cutaneous cancer either by a dermatologist or investigators trained on studying arsenic toxicity. Organ damage and other systemic toxicity symptoms are only studied at later stages through different clinical tests to arrive at a positive conclusion. Arsenic toxicity can be determined by testing for its levels in water or for clinical diagnosis in the hair, nails as well as urine of the affected individual [8]. Melanosis can be reversed with medications, while keratosis becomes a permanent damage. Also, arsenicosis induced by contaminated drinking water can be reversed/controlled by avoiding intake of the same.

Awareness as well as measures for cleanup and counseling of the affected becomes the only way to tackle arsenic toxicity. Also, statistical evidence gathering becomes a must to understand prevalence as well as the affected areas. Though studies on water testing for arsenic are documented in India, levels of the same in the human body have not been widely studied. Our report is an attempt to highlight average levels of arsenic in blood samples from a pan-India cohort. Ideally, blood arsenic levels are used to identify recent exposure. The levels vary considerably in health subjects depending on exposure through diet and environment. Urine arsenic levels are used to identify chronic exposure.

Section snippets

Cohort

The study consisted of a total of 205,530 subjects including both males and females of different age-groups. The total number of females in the study group was 93,793 while the total number of males was 111,737 respectively. The entire study cohort has been summarized in Table 1.

Methodology

Arsenic levels were measured in whole blood samples procured in EDTA Vacuette tubes using the robust analytical platform of ICP-MS (Inductively Coupled Plasma - Mass Spectrometry; Thermo Fischer Scientific). Sample

Results

Arsenic levels of up to 5 μg/L were reported to be normal considering our validation studies and also reports suggesting average levels of arsenic in blood of unexposed individuals lie anywhere between 0.3–2 μg/L [9]. The frequency of high arsenic levels (≥ 5 μg/L) detected in the study was 1.37%, with the frequency of 1.47% in males and 1.25% in females respectively. This difference in frequency between genders is found to be statistically highly significant with χ2 value of 18.49 and the

Discussion

Arsenic being a metalloid is documented to be a part of more than 245 minerals and is also one of the most abundant on the Earth's crust [10]. Prolonged exposure to arsenic, leads to arsenicosis characterized majorly by skin pigmentation and also systemic manifestations. The time taken for the adverse effects to show however is extremely dose dependent. The first report to highlight the non-dermatological features of arsenic poisoning in India due to contaminated water was documented in the

Conclusion

Arsenic contamination from groundwater continues to be the major source of toxicity and the drilling of borewell for water conservation is done even in metros. With no specific treatment option proven beneficial till date in chronic arsenic toxicity cases, use of surface water and safe harvest of rain water in affected areas becomes the best solution to tackle this menace. Also, mass screening camps in healthy individuals must be undertaken in a similar fashion to keep charting exposures.

Conflict of interest

None.

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