Did you know your drinking water may be poisoned? Yes, you could be drinking water with Arsenic without knowing, which could cause severe poisoning and be very dangerous for human health.
Arsenic (As) is the 53rd most abundant element on Earth, and it is found mainly on its crust. Despite its low abundance, it is widely believed that Arsenic can be dissolved from the minerals present on groundwater’s surrounding rocks. Water can be contaminated typically by the inorganic forms of Arsenic called Arsenious Acid and Arsenic Acid. Unfortunately, these are some of the most toxic common compounds of all.
Industrial and agricultural sources can also contaminate water. Arsenic is used in alloys and the manufacturing of glass, pigments, textiles, paper, metal adhesives, wood preservatives, ammunition, and hide tanning processes. It is employed in pesticides, fertilizers, and feed additives in the agriculture world. Also, it is used in minimal doses in some drugs for treating syphilis, trypanosomiasis, psoriasis, and even leukemia. Once released into the environment, it could remain there for several tens of years.
People can then be exposed to drinking water with Arsenic under elevated concentration through contaminated water or using water with Arsenic in food crops irrigation and cooking. Human health can be seriously affected by exposure to Arsenic. Acute symptoms for high and punctual arsenic doses include vomiting, diarrhea, and abdominal pain. This is followed by numbness and tingling of the extremities, muscle cramping, and death in extreme cases.
Long-term Arsenic exposure produces skin signals as the first symptoms of poisoning. These can be pigmentation changes, skin lesions, and hyperkeratosis, a skin thickening condition where hard patches are formed on the palms and soles of the feet. Also, all arsenic compounds are considered carcinogenic agents. It is believed that a time exposure of approximately five years could lead to skin cancer, as well as bladder and lung cancer. Other adverse effects associated with long-term Arsenic exposure are development defects, diabetes, pulmonary and cardiovascular diseases.
For example, the “Blackfoot disease” (poor vascular irrigation on the feet) is frequently associated with long-term ingestion of Arsenic in China. Also, the exposure of the fetus at the mother’s womb or in early childhood is related to a mortality increase in youngsters by cancer or cardiopulmonary diseases. Negative effects on cognitive, memory, and mental development have been reported too.
Due to the wide range of diseases mentioned above and the high probability to have Arsenic contamination of our drinking water, several strategies have been developed to address this situation. According to the World Health Organization (WHO), nearly 140 million people in 50 countries can be exposed to contaminated water. WHO recommends a provisional guideline value of 10 μg/L of Arsenic in drinking water.
Water with Arsenic under Natural Conditions
Some regions of Earth are more susceptible than others to arsenic contamination due to their soils’ rock formation. In such locations, Arsenic poisoning is commonly called Endemic Regional Chronic Hydroarsenicism or, by its acronym in Spanish, HACRE. Pakistan, Argentina, Chile, and Nepal are examples of these regions, with Bangladesh being the most dramatic case.
In Bangladesh, the problem is severe because ineffective water purification and sewage systems are overrun by the regular monsoon season, which floods the entire area. Several international organizations, such as UNICEF and the World Bank, recommend a depth for drinking water wells between 20 and 100 m. This is due to water in higher aquifers could be a shorter time underground and hence a shorter exposition to Arsenic. Such a policy has permitted to reduce child mortality by five percent. However, it is still insufficient. Approximately 900 more villages present water with Arsenic concentration levels higher than the government’s limit.
In South America, most HACRE affected regions comprise Uruguay, Argentina, and Chile, with a more negligible effect on Bolivia, Peru, and Paraguay. In Uruguay, Arsenic levels can be between 0.1 – 58 μg/L while Chile ranges between 200 – 900 μg/L, and Argentina is 100 – 6000 μg/L. The affected population is about one million people, mostly living in rural and isolated communities.
What can we do? Unfortunately, boiling the water does not resolve the problem because this process slightly increases water’s arsenic concentration. The real solution for this type of contamination comes from applying several sources of water treatments: physical, chemical, and biological treatments.
The more straightforward strategy consists of applying water treatment right after leaving the distribution site with a temporary facility. Water is passed through filters containing iron, activated carbon, and sand to remove Arsenic. Filters made to activated silica, or titanium oxide, have also been used.
Long-scale solutions should use several types of water treatment simultaneously due to the complex chemistry of aqueous Arsenic. Sophisticated methods include iron oxide adsorption, ion-exchange resins, iron electrocoagulation, and electrodialysis.
The Biological solution is called Subterranean Arsenic Removal (SAR) technology that involves the usage of arsenic-oxidizing microorganisms, which are capable of converting them into less toxic compounds. No chemicals are employed, whatever leads to minimal waste disposal. Current trends are focused on using nanoparticles or nanocomposites, particularly iron. The arsenic adsorption capacity of the composite is 1.4 to 7.6 times better than the available compositions in field conditions.
In Easy Clean Water, we believe this is a field worth considering because it follows our value proposition. The local population doesn’t have the resources to sustain these sophisticated types of water treatment, requiring more governmental resources allocation, which compromises the well-being of future generations.