How much arsenic in water is dangerous?

While the PGS of the University of Natural Sciences confirmed that the arsenic content in drinking water below 0.05mg / l is safe, the representative of the Ministry of Health affirmed that the standard is 0.01mg / l. giving is new is safe.

>>>Bewildered because of water poisoning

Controversy

The closure of My Dinh 2 Water Supply Station due to the excess of 1.8 times the arsenic level is causing many people to worry.

Regarding the My Dinh 2 water supply station (Nam Tu Liem district, Hanoi), it was closed because the arsenic content in the country exceeded the Ministry of Health's standards by 1.8 times, and interviewed VietNamNet Newspaper, Assoc. Tran Hong Con, lecturer of Faculty of Chemistry, University of Natural Sciences confirmed that the arsenic content in water is 2 times higher than 'still in safe range'.

PGS Con cited that, according to studies in Bangladesh, water users have arsenic levels below 0.05mg / l, after 5-10 years there is no sign of arsenicosis. Only those who use arsenic-contaminated water are above 0.05mg / l and especially 0.1mg / l, the arsenic infection will appear after about 3-5 years of use.

In response to this view, PGS Nguyen Huy Nga, Director of the Department of Health Environmental Management (Ministry of Health) affirmed, there have been many studies around the world that show that the consumption of arsenic contaminated drinking water affects health. healthy with different levels. This harmful effect depends on the exposure time, exposure level, arsenic concentration in drinking water.

Recognizing that the health impact of exposure to arsenic at a concentration below 0.05 mg / l is less evident, but Russia said that the cause may be due to its impact mainly. Out at the cellular level our naked eyes are not visible.

'Arsenic is known to be able to accumulate in the body and inhibit 200 different enzymes, thereby affecting chemical reactions and metabolism processes in the body. Many recent studies have shown that arsenic at very low concentrations, below 0.02 mg / l, can cause endocrine disruption , "said Russia.

Mr. Nguyen Huy Nga, Director of the Department of Health Environmental Management, Ministry of Health.(Photo: Vietnam +)

A study published in the journal Environment Health Perspect, conducted in 42 villages in Taiwan in 2000 showed that with the standard for arsenic in drinking water of 0.05mg / l, it will increase significantly. risk of causing cancer to the community and will not be able to protect public health, he added.

In his argument, Associate Professor Tran Hong Con also said that people living in My Dinh 2 urban area need not worry too much because at some private wells of the US as well as some other countries and territories , people still use 0.05 mg / l standard and below this threshold is still safe.

In this regard, Associate Professor Nguyen Huy Nga affirmed that in the US, US Environmental Protection Agency (USEPA) reduced arsenic standards in drinking water from 0.05 mg / l to 0.0101 mg / l into in 2001 and towards zero regulation. This standard applies to all public water suppliers and no exceptions.

'For private well water, because the US does a good job of protecting the environment, minimizing the risk of groundwater pollution, so whether or not to regulate standards for arsenic depends on each state ' , Mr. Nga said.

Rural areas still use 0.05mg / l standard

Recognizing that the World Health Organization (WHO) has recommended that the level of 0.01 mg / l is absolutely safe, there is no other risk, but PGS Con thinks that Vietnam only applies WHO recommendations, without any specific research on the situation in Vietnam, with the conditions of physical, economic and epidemiological hygiene of Vietnamese people.

Arsenic standards for domestic water in rural households are still 0.05 mg / l.

Moreover, PGS Con also said that in the past, Vietnam used standard 0.05 mg / l for a long time and then lowered it to 0.01 mg / l today. And currently, arsenic standards in domestic water, which are exploited by households in rural areas, still apply this standard (QCVN 02: 2009 / BYT).

'This is the clearest evidence that, 0.05 mg / l arsenic content is still not dangerous. Because now, in rural areas, we are still using this threshold. Perhaps, rural people are stronger than urban people? ' , Associate Professor Tran Hong Con raised the issue.

In this regard, Assoc. Prof. Nguyen Huy Nga also acknowledged that setting the 0.05mg / l standard for rural water is a 'concession' because conditions for treating rural water are not equal to urban areas.

However, the representative of the health sector also affirmed that when developing guidelines for drinking water standards, WHO also recommends that countries can base on the actual capacity of each country (eg water treatment technology, cashew socio-economic conditions, arsenic contamination levels .) to consider applying accordingly.

Up to now, many countries have applied the arsenic standards 0.01mg / l as European countries, America, Taiwan, Japan, Korea, Singapore . In Australia, arsenic regulation is only 0.007mg / l. .

'For Vietnam, because the groundwater source is heavily polluted, so groundwater exploited by households needs to have a more suitable quality standard for use for domestic purposes , ' Mr. Nga explained.