28-Jul-2018: Arsenic contamination in paddy is rising in Bengal

A recent publication by researchers at the School of Environmental Studies (SOES), Jadavpur University, reveals not only rise in arsenic contamination of paddy plants from ground water in West Bengal, but also that concentration of ‘arsenic accumulation’ depends on the variety of paddy and its stage in the crop cycle.

Highlights of the study:

• The study highlights the processes and dependencies of arsenic trans-location in rice from contaminated irrigation water.
• The study shows that arsenic uptake in the paddy plant reduces from root to grain, and that its concentration is related to the variety of the rice cultivated.
• The uptake of arsenic is faster in young roots in a vegetative state than in older tissues with a higher concentrations of iron in root soil in the reproductive phase.
• The study was carried out on two commonly consumed rice varieties — Minikit and Jaya — and the latter was found to be more resistant to arsenic.
• The study has raised concerns over the disposal of the contaminated rice straw which is used as animal fodder or burnt or sometimes left in the field itself to serve as fertiliser.

Arsenic in groundwater: Arsenic in ground water is a geogenic contaminant i.e. caused by natural geologic processes. Incidence of high arsenic in groundwater reported from various parts of the country, particularly in the Ganga- plains is a serious threat to the health of human being.

Over the last three decades numerous measures have been initiated which includes alternate arrangement for supply of arsenic free water to the affected populace and providing arsenic removal plants. Arsenic occurrences in ground water in these areas is highly sporadic in nature and all the sources in these areas are not necessarily contaminated.

Technological options to combat arsenic menace, in groundwater, to ensure supply of arsenic free water, in the affected areas can be in-situ remediation of arsenic from aquifer system, ex-situ remediation of arsenic from tapped groundwater by arsenic removal technologies, use of surface water source as an alternative to the contaminated groundwater source, tapping alternate safe aquifers for supply of arsenic free groundwater or combination of above techniques.

19-Mar-2017: 1.04 crore people hit by arsenic contamination in Bengal.

A recent report tabled in the Lok Sabha stated that West Bengal has the highest number of arsenic-affected people in the country.

According the report, Bengal topped the list with more than 1.04 crore arsenic-affected persons as on March 4, 2017. Bihar comes second with 16.88 lakh persons, with Assam in third spot with 14.48 lakh victims. The total number of arsenic-affected people in the country is about 1.48 crore.

There are 83 blocks in eight districts — Bardhhaman, Malda, Hooghly, Howrah, Murshidabad, Nadia, North and South 24 Parganas — where ground water is affected by arsenic contamination.

According to the WHO’s guidelines for drinking water quality (2011), the permissible limit of Arsenic in groundwater is .01 mg per litre. However, in India the permissible limit in drinking water has recently been revised from .05 mg per litre to .01 mg per litre.