Arsenic Induced Breast Cancer Risk in Population of Bihar, India

Abstract Globally, ~ 300 million people are exposed to arsenic poisoning while in India an estimated 70 million people are affected by consumption of arsenic contaminated water. The state of Bihar is an endemic belt for arsenic contamination in groundwater affecting over 10 million people with moderate to serious health manifestations. Life threatening disease like cancer is not uncommon now, and carcinoma type of cancer cases are on the rise. Breast cancer incidences in the state follows closely with more and more women getting affected. Approximately, 23% of the cancer types in women are related to breast cancer, diagnosed at a fairly advanced stage (III or IV) of the disease. The etiology of the disease is not clearly known though faulty lifestyle and genetic makeup cannot be ruled out. The present study attempts to derive a relation between increasing breast cancer cases with the sustained arsenic intake in the second most populated state of the country. Pathologically confirmed, female breast cancer patients (n = 55) from across the state were included in the study. Sampling of the breast tissue, blood, hair and toe nail was carried out by the surgical oncology department of the institute. As a part of cross-sectional study, (n = 12) female breast benign cases were taken as the control group and their biological samples were also collected. All the samples as per the protocol of NIOSH were digested and analysed by graphite furnace atomic absorption spectrophotometer. For the epidemiological parameter study, their age, type of malignancy, stage and demographic information was compiled. The results were correlated with the arsenic concentration in groundwater as per their endemic status and anomalous values on GIS platform. The role of geological studies to establish the morpho-stratigraphic control and aquifers with higher concentration was brought to use. The results are fairly indicative of the high correlation of anomalous concentration of arsenic with the sample population with diagnosed malignancy as compared to the control group. The maximum arsenic concentration observed in the biological samples in blood was 1856µg/L, in breast tissue 446.4µg/Kg, in hair 1296·9µg/Kg and in toenail 621·83µg/Kg respectively. The scattered plots correlate the relationship between age of the breast cancer patients with arsenic contamination, while the geospatial distribution positively correlates with the districts with increased arsenic endemicity in a predominantly alluvium dominated country. The high arsenic contamination in the biological samples of the breast cancer patients is an indicative marker to the possible relation of the disease to arsenic, as compared to the control population exposed to a much lesser toxicity. Consumption of water with more than 10 ppb arsenic contamination over a sustained longer time span has possibly exposed the population to a larger threat to disease as inferred from the findings. The disease breeding as a silent killer with reduced or unnoticeable symptoms upto a fairly advanced stage has further accentuated the problem. The present study thus endeavours to identify a significant relation of the disease with sustained intake of arsenic consumed through water and food products laden with anomalous concentration.