Removing Arsenic from Groundwater: We Have the Tools, Let’s Use Them

Credit: Hafiz Johari / Shutterstock.com

By Yina Shan, Praem Mehta, Duminda Perera, & Yurissa
Varela
HAMILTON, Canada, Feb 1 2019 (IPS)

Cost-effective technologies are available to remove arsenic in
groundwater. Why then do tens of millions still fall ill to this
chronic problem?

High natural levels of arsenic are characteristic of the
groundwater supply in many countries, including Bangladesh, India,
Nepal, Mongolia, and the United States.

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.

At least 140 million people in 50 countries have drinking water
containing arsenic at levels above the World Health Organization
(WHO) guideline — 10 μg/L (micrograms per litre). In some
places, people are using groundwater with arsenic levels 10 times
or more the WHO’s recommended limit.

This exposure, through drinking water and crops irrigated with
contaminated water, can lead to severe health, social and economic
consequences, including arsenicosis (symptomized by muscular
weakness, mld psychological effects), skin lesions, and cancers
(lung, liver, kidney, bladder, and skin). The social implications
of these health impacts include stigmatization, isolation, and
social instability.

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 US$
13.8 billion in about 10 years.

There are many technologies today that, broadly speaking, use
one of six approaches to remove arsenic, described in an abundance
of scientific studies. Between 2014 to 2018 alone, over 17,400
papers were published describing elements of the problem and a
myriad of low-cost treatment technologies.

A report, published by the UN University’s Canadian-based
Institute for Water, Environment and Health, draws on 31
peer-reviewed, comparable research papers that appeared between
1996 and 2018, each describing new technologies tested in
laboratories and / or in field studies. The papers covered:

* 23 lab-tested technologies that used groundwater from nine
countries (Argentina, Bangladesh, Cambodia, China, Guatemala,
India, Thailand, the United States, and Vietnam) and demonstrated
arsenic removal efficiencies ranging from 50% to almost 100%, with
a majority reaching over 90%. About half achieved the WHO standard
of 10 µg/L.

* 14 technologies tested at the household or community level (in
Argentina, Bangladesh, Chile, China, India, and Nicaragua) achieved
arsenic removal efficiency levels ranging from 60% to about 99%,
with 10 removing more than 90%. Only five reached the established
WHO standard.

For lab-tested technologies, the cost of treating one cubic
meter of water ranged from near-zero to about US$ 93, except for
one technology (US$ 299 per m³). For field tested technologies,
the cost of treating a cubic meter of water ranged from near-zero
to about US$ 70.

No single technology offers a universal solution, but the report
helps point to remedies likely to prove most economical and
efficient given the many variables present in different locations
worldwide.

Key factors influencing removal efficiencies and costs are:

• the arsenic concentration of the
influent water,
• pH of the influent water,
• materials used,
• the energy required,
• absorption capacity,
• labour used,
• regeneration period and
• geographical location

The report also notes that a technology can only be considered
efficient if it successfully removes arsenic to a level that meets
or exceeds the WHO standard of 10 µg/L.

Bangladesh, China and India and some other countries with
resource constraints or certain environmental circumstances –
such as very high arsenic concentrations in groundwater – set
higher, easier-to-reach national arsenic concentration targets.

In Bangladesh, for example, where the nationally-acceptable
arsenic limit in water is set to 50 µg/L, it’s estimated that
more than 20 million people consume water with arsenic levels even
higher than the national standard.

Globally, despite international efforts, millions of people are
exposed to arsenic concentrations reaching 100 µg/L or more.

While national limits higher than the WHO standard may help
policymakers report better arsenic reduction results, if a country
feels that the situation is coming under control it may reduce the
sense of urgency in policy circles to eradicate the problem, and
the population continues to suffer from ingesting high levels of
arsenic.

A limit less stringent than the WHO guideline effectively shifts
attention from the problem and impacts and postpones the best
health outcome for citizens — and needlessly so, given the
technologies available.

The technologies in hand today can significantly reduce the
numbers of people affected by this public health problem. Needed is
a sustained, concerted effort from policymakers, engineers,
healthcare providers, donors, and community leaders to achieve
quantifiable and sustainable impacts.

Over the next decade, we need wide-scale implementation of
remediation solutions to meet the WHO standard and achieve two key
Sustainable Development Goals: SDG 3 (“Good health and
wellbeing” and SDG 6 (“Clean water and sanitation”).

We have cost-effective tools to alleviate and ultimately
eradicate the problem of arsenic-contaminated water consumption.
Let’s use them.

The post
Removing Arsenic from Groundwater: We Have the Tools, Let’s Use
Them
appeared first on Inter
Press Service
.

Excerpt:

Researchers Yina Shan, Praem
Mehta
, Duminda Perera and Yurissa
Varela
developed this report at the UN University
Institute for Water, Environment and Health, hosted by the
Government of Canada and McMaster University

The post
Removing Arsenic from Groundwater: We Have the Tools, Let’s Use
Them
appeared first on Inter
Press Service
.

Source: FS – All – Ecology – News
Removing Arsenic from Groundwater: We Have the Tools, Let’s Use Them