Why do you think your paper is highly cited?

It identified that inorganic arsenic, a non-threshold, class 1 carcinogen, was elevated in rice grain from particular regions of the world, with that elevation being due to anthropogenic sources.

 Does it describe a new discovery, methodology, or synthesis of knowledge?

It was the first paper to widely survey the inorganic arsenic content of rice, and to establish what constituted background and elevated levels. It also was the first to establish regions of the world at threat from high inorganic arsenic in rice.

 Would you summarize the significance of your paper in layman’s terms?

The study identified rice, the dietary staple for half the world, as the major route of the carcinogen inorganic arsenic into the human diet.

 How did you become involved in this research and were any particular problems encountered along the way?

I had a long history of studying the physiology of arsenic metabolism in wild plants, but researching rice started when a Ph.D. student whom I was supervising came from Bangladesh to study arsenic in rice, as he had realized that problems may be occurring due to the practice of irrigating rice with arsenic-contaminated tubewell water. Once we started to look into arsenic in rice grain, we realized that this was a major problem with respect to human dietary exposure from this carcinogen.

 Where do you see your research leading in the future?

We have currently obtained major grant funding to breed rice with a lower inorganic arsenic content, and, through this process, to identify the genetics and physiology behind rice grain arsenic accumulation.

 Do you foresee any social or political implications for your research?

Yes, there are no food standards for inorganic arsenic in the USA and EU or set by the World Health Organization. The EU, as a direct result of our research, is currently reviewing this topic. In the UK, the government has already issued warning advice that children under the age of 4.5 years should not be fed rice milk.

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RESEARCH ACTIVITIES

Present research activity is very much focused on arsenic, and in particular arsenic issues affecting SE Asia. The work on arsenic is both the environmental chemistry and plant ecophysiology.

Environmental chemistry aspects of the work is interested in arsenic sources and cycling within the environment, using state of the art analytical approaches such as XAS and HPC-ICP-MS, HPLC-ES-MS-MS and laser ablation-ICP-MS to study arsenic speciation in biotic and abiotic matrices such as soils, sediments, minerals, plant & animal tissues. The work concentrates on human and wild-life exposure to arsenic through food-chains, and the microbial mechanisms regulating arsenic transformations in the environment.

Plant ecophysiological aspects of the arsenic research investigates mechanisms of arsenic uptake, internal transport and metabolism, particularly how on how plants adapt to high levels of arsenic, the genetic mechanisms behind adaptations, with the aim of breeding crop plants, such as rice and wheat, for low grain arsenic.

Grain studies have been expanded to consider other toxic elements (cadmium and lead) and well as essential trace micronutrients (copper, selenium & zinc).

Professor Andrew A. Meharg
Fellow of the Royal Society of Edinburgh
Chair in Biogeochemistry
Institute of Biological & Environmental Sciences
University of Aberdeen
Web | Web

KEYWORDS: ELEMENTAL CONTENT; DRINKING-WATER; UNITED-STATES; ORYZA-SATIVA; WEST-BENGAL; BANGLADESH; FOOD; CONTAMINATION; TOXICITY; SOILS.