A UNIDO-funded study on the assessment of arsenic in rice growing areas of Pakistan finds that the levels of arsenic in the investigated varieties do not currently seem to be a risk.

Findings have proved that arsenic in rice crops relatively a newfangled issue in Pakistan and its direct linkages with irrigation water may not be clearly visible.

However, the study stresses more attention be given to the use of irrigation water as drinking water, arsenic accumulation in topsoil and arsenic uptake capacity of rice varieties in order to safeguard public health and foreign exchange earnings through rice export.

The study, carried out by the Pakistan Council for Research in Water Resources and released last week, recommends development of new irrigation strategies, adoption of modern irrigation system with due consideration of water quality, preference to surface water irrigation systems ( since surface water is arsenic-free), growing of arsenic resistant varieties and monitoring of irrigation water and rice grains.

No sample was found exceeding the WHO recommended permissible limit of 1.00 mg/kg for arsenic

Pakistan is one of the world’s largest producers of rice with an average annual output of six million tonnes and together with the rest of the South Asian region, the country is responsible for supplying 25pc of the world’s paddy output.

Human exposure to arsenic via rice consumption is of increasing concern. Rice is one of the most important food crops around the world and feeds over half of the global population. Studies have shown that high concentrations of arsenic in soil and irrigation water often lead to high levels of arsenic in crops and are posing an increased food safety risk.

The Codex Alimentarius Commission Committee on Contaminants, which sets a maximum limit to arsenic in rice, at its last meeting held in the Netherlands, supported the participation of the National Animal Plant Health Inspection Services (NAPHIS) at the committee’s meeting, and as a prerequisite for the meeting, the baseline assessment of arsenic in a number of rice varieties grown in Pakistan.

To quantify the distribution of arsenic in various varieties grown in different areas of Pakistan — Gujranwala, Gujrat, Hafizabad, Kasur, Lahore, Mandi Bahauddin, Narowal, Okara, Sheikhupura and Sialkot — samples were collected from rice processing mills, storages, whole-sellers and open market.

The maximum levels of arsenic of all the samples were found in the range of 84.75 to 356.20 ppb (0.084 to 0.356 mg/kg). None of the sample was found exceeding the 1.00 mg/kg, the World Health Organisation (WHO) recommended permissible limit for arsenic.

The assessment study observes that the irrigation development is foreseen to rely largely on ground water abstraction. There is a high risk, if proper control measures are not taken and the ground water resources are not managed properly, that the use of arsenic contaminated ground water may turn out to be hazardous in the future.

This situation does not seem alarming yet but needs to be taken very seriously and proper measures need to be taken to deal with the possible threat posed by arsenic contamination, while implementing irrigation practices.

The study also recommends that the water quality of any new irrigation scheme be assessed prior to approving it. In addition, farmers should be educated for arsenic testing of their irrigation water, rice and other crops yield.

Published in Dawn, Business & Finance weekly, February 15th, 2016