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, is it widely believed that Arsenic can be dissolved from the minerals presents on the surrounding rocks of groundwater. 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.
Water can also be contaminated by industrial and agricultural sources. Arsenic is used in alloys, as well as in the manufacturing of glass, pigments, textiles, paper, metal adhesives, wood preservatives, ammunition, and hide tanning processes. In the agriculture world, it is employed in pesticides, fertilizers, and feed additives. Also, it is used in minimal doses in some drugs for treating syphilis, trypanosomiasis, psoriasis, and even leukemia. Once it is 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, as well as for cooking. Human health can be seriously affected by the exposure of Arsenic. Acute symptoms for high and punctual arsenic doses include vomiting, diarrhea, and abdominal pain. 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, which is 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 considered 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 an in 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) near to 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 of having Arsenic contamination due to the rock formation of their soils. 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, being Bangladesh the most dramatic case.
In Bangladesh, the problem is very serious because ineffective water purification and sewage systems are overrun by periodic 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 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 the countries Uruguay, Argentina, and Chile, with less effect on Bolivia, Peru, and Paraguay. In Uruguay, Arsenic levels can be between 0.1 – 58 μg/L while Chile has a range between 200 – 900 μg/L, and Argentina is 100 – 6000 μg/L. The affected population size is about one million people, mostly living in rural and isolated communities.
What can we do? Unfortunately, boiling the water not resolve the problem, because this process contributes to increasing slightly water’s arsenic concentration. The real solution for this type of contamination comes from the application of several sources of water treatments: physical, chemical, and biological treatments.
The simpler strategy consists of applying water treatment right after it has left 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 been used too.
Long-scale solutions should be using several types of water treatment simultaneously due to the complex chemistry of aqueous Arsenic. Sophisticated methods that 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 to convert it into less toxic compounds. No chemicals are employed, whatever leads to minimal waste disposal. Current trends are focused on using nanoparticles or nanocomposites, particularly of 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 a field worth taking into consideration 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.