Time demands better technology to lessen the arsenic levels in consumable water
At least 140 million people in 50 countries consume water containing arsenic at levels above the World Health Organization (WHO) guideline -- 10 mg/l.
In some places, people are using groundwater with arsenic levels 10 times or more than WHO’s suggested frontier.
Apart from that, the proctorial body of the United Nations is concerned towards the goals of SDGs 3 (good health and well-being) and 6 (clean water and sanitation).
Arsenic-related health problems lead to significant economic losses due to lost productivity in many places.
In Bangladesh, where the groundwater arsenic problem is most acute, the economic burden from lost productivity is expected to reach an estimated $13.8 billion in about 10 years.
This exposure, through drinking water and crops irrigated with contaminated water, can lead to severe health, social and economic consequences, including arsenicosis (muscular weakness, mild psychological effects), skin lesions, and cancer (lung, liver, kidney, bladder, and skin).
Apart from that, the social implications of these health impacts include stigmatization, isolation, and social instability.
Cost-effective technologies are available to remove arsenic in groundwater.
High natural levels of arsenic are characteristic of the groundwater supply in many countries, including Bangladesh, India, Nepal, Mongolia, and the US.
Some of the contamination is caused by mining, fertilizers, and pesticides, waste disposal, and manufacturing, but mostly it is due to arsenic leeching -- dissolved from rocks underground by highly acidic water.
A recont report draws on 31 peer-reviewed, comparable research papers that appeared between 1996 and 2018, each describing new technologies tested in laboratories.
Research from nine countries (Argentina, Bangladesh, Cambodia, China, Guatemala, India, Thailand, the United States, and Vietnam) demonstrates arsenic removal efficiencies ranging from 50% to almost 100%; where 14 technologies tested at a community level (in Argentina, Bangladesh, Chile, China, India, and Nicaragua) achieved arsenic removal efficiency levels ranging from 60% to about 99%.
In general, the key factors influencing removal efficiencies and costs are: The arsenic concentration of the influent water, ph levels of the influent water, materials used, the energy required, absorption capacity, labour used, regeneration period, and geographical location.
Dhaka, Beijing, and New Delhi -- and some other states with certain environmental hazards such as very high arsenic concentrations in groundwater -- situate higher, easier-to-reach national arsenic concentration targets.
In Bangladesh, for example, where the nationally-acceptable arsenic limit in water is set to 0.5 mg/l, it’s estimated that more than 20 million people consume water with arsenic levels even higher than the national standard.
The technologies today can significantly lessen the number of people affected by this public health hazard.
Time demands a sustained, concerted effort from policymakers, engineers, health care providers, donors, and community leaders to achieve quantifiable and sustainable positive impacts.
Shishir Reza is an environmental analyst and associate member of Bangladesh Economic Association.