Drinking the disease: A family affected by arsenic in well water

INTRODUCTION Worldwide, it is estimated that over 220 million people in 56 countries are exposed to unsafe concentrations of arsenic derived from their drinking water and food.1 The highest levels are found in the groundwater of Argentina, Bangladesh, Cambodia, Chile, China, India, Mexico, Pakistan, the United States and Vietnam.2 Canadians are also exposed to arsenic through multiple conduits including in food, soil, ambient air and drinking water.3 In Canada, over 3 million Canadians, or 10% of the total population, obtain their drinking water from private wells.4 In one report from Nova Scotia, the provincial government reported that 42% of residents rely on private wells, and it is estimated that one in five of these private well users may have unsafe levels of arsenic in their untreated water.5 In addition, a news report from 2022 warned of exceptionally high arsenic levels in the groundwater in Newfoundland.6 Shortly thereafter, the provincial government announced it would supply 2000 free test kits to well owners as part of a groundwater study.6 In the United States where we practise, over 44 million people use water from domestic private wells, with 2.1 million of these estimated to have arsenic levels above 10 ppm, which is the maximum internationally established threshold.7 In Wisconsin where our patients live, it is estimated that 25% of residents (1.5 million people) acquire their drinking water from private wells.8 Arsenic is most frequently found due to prior geological glacial exposure, consequentially resulting in substantial amounts of the mineral in ground deposits nation-wide.9 Arsenic cannot be tasted, seen or smelled and can vary in concentration in home water samples even in neighbouring areas.7 Previous research has explicated that if arsenic is not identified and filtered from potable water, a variety of frequently seen medical conditions may arise from chronic exposure, some of which are life-threatening.10 These include lung, renal, bladder and skin cancers, as well as type 2 diabetes mellitus, hypertension, polyneuropathy and cardiac QTc prolongation.10,11 Non-specific cutaneous lesions such as thickening of the palms and soles are also associated with arsenic toxicity, comprising an important physical manifestation physicians need to be aware of.12 More recent research adds neurological disorders as a potential symptom, with a contributory role of environmental arsenic in mitochondrial dysfunction and neurotoxicity.13 In their study of children’s exposure to arsenic-containing well water, Wasserman et al. reported that ‘exposure to arsenic was associated with reduced intellectual function after adjustment for socio-demographic covariates’.14 CASE REPORT A 25-year-old man and his wife moved to Wisconsin in December of 2021 into a house built in the 1970s. At the time of moving, they were aware that they had poor water quality despite the home’s water treatment system, which included a neutraliser, water softener and filtering unit. The owners installed a reverse osmosis system 1 month later, assuming it would remove any harmful components from the water they used for daily drinking and cooking. The owners then installed a polyvinyl chloride well liner 5 months later, in May of 2022, with the hope of improving the water’s appearance, but saw no improvement. Approximately 1 year after moving in, in February of 2023, the patient first began to experience vague symptoms consisting of vision changes, dizziness, disorientation, brain fog and transient neuropathy in his lower extremities. The symptoms became progressively worse and caused concern for him and his wife. At the same time, their newborn daughter, born in January 2023, had developed a persistent nocturnal cough without a clear aetiology. Neither parent smoked. The patient did not seek formal medical care as his wife is a physician assistant. In April 2023, the patient’s wife ordered a hair mineral analysis due to concern for potential heavy metal toxicity. The results showed an elevated arsenic level of 0.41 parts per million (ppm), with normal being <0.03 ppm [Table 1]. They surmised that the non-reverse osmosis-treated water being used for bathing contained arsenic, causing a high reading on the hair test. They continued to drink the reserve osmosis-treated water. The following month, the patient’s wife’s hair mineral analysis also returned with high levels of arsenic (0.52 ppm).Table 1: Timeline and results of arsenic hair analysis levels of patient and his wifeWith appropriate suspicion, the couple tested their well water for arsenic and found the level to be 40 ppm, much higher than the international standard for drinking water of <10 ppm. They analysed their reverse-osmosis-treated water and found it still contained 20 ppm of arsenic. They decided to drill a new deeper well into the aquifer further away from the home at that time. Their arsenic levels were thereafter tested to be below detectable levels. The parents realised that they were still using the reverse-osmosis-filtered water from their initial well (still with significant arsenic concentration) for a humidifier in their daughter’s bedroom. The infant was exclusively breastfed, so she did not ingest any contaminated water. As Duan et al. note, ‘The use of ultrasonic humidifiers filled with tap water poses an arsenic inhalation risk. In addition to drinking water intake, inhalation is also an important route of arsenic exposure’.15 The patient and daughter’s symptoms eventually resolved months following the installation of the new well. Both parents’ hair analyses in November 2023 were below normal limits (0.005 and 0.002, respectively). DISCUSSION Since private well testing is not done by local authorities or public health officials, it is up to the well owners to assess their water and filter arsenic through commercially obtained water filters, although based on existing research, we know that this is infrequently done.16 Aside from organic arsenic found innately in groundwater, inorganic arsenic is also an ingredient in pesticides and was previously used as a wood preservative. Although this wood treatment process has been discontinued, the ongoing leaching of residue from treated wood has been reported as a continuous source of contamination in soil and water.17 The homeowners are confident that their groundwater was contaminated from the treated wood foundation of their home, as their old well was shallow and only three feet away from the foundation. The owners also tested three other wells on properties they own nearby (0.91 miles, 0.85 miles and 0.30 miles away), two with arsenic levels being undetected and one at 2 ppm. All three were a significant distance from any home foundation. CONCLUSION This case study illustrates the importance of a thorough history and assessment of environmental aetiologies of clinical presentations. High levels of arsenic in well water may serve as a cause of varied and serious symptomatology in patients of all ages. It is important to ask patients about their principal water source when faced with vague and unusual symptoms, particularly in rural areas. Declaration of patient consent The authors certify that they have obtained all appropriate patient consent forms. In the form the patient (s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed. Financial support and sponsorship: Nil. Conflicts of interest: There are no conflicts of interest.

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