last few years, researchers have reported high concentrations of arsenic in
several rice-growing regions around the world.
University of Manchester scientists, working in collaboration with scientists
at CSIR-Indian Institute of Chemical Biology in Kolkata, have proven a link
between rice containing high levels of arsenic and chromosomal damage, as
measured by micronuclei* in urothelial cells, in humans consuming rice as a
researchers discovered that people in rural West Bengal eating rice as a staple
with greater than 0.2 mg/kg arsenic showed higher frequencies of micronuclei
than those consuming rice with less than this concentration of arsenic.
published in Nature Publishing Group's Scientific Reports, looked at the
frequency of 'micronuclei' – a tell-tale sign of chromosomal damage (that has been
shown by others previously to be linked to cancer) – by screening more than
400 000 individual cells extracted from urine samples from volunteers.
funded by the UK India Education and Research Initiative (UKIERI), chose a
study population with relatively similar dietary and socio-economic status that
was not otherwise exposed to arsenic, for example, through drinking water.
demonstrated that the trend of greater genetic damage with increasing arsenic
in rice was observed for both men and women, for tobacco-users and non-users,
and for those from three different locations within the study area.
observed was broadly similar to that previously seen for people exposed to
arsenic through drinking high arsenic well waters, which has caused devastating
health impacts, including cancers, in many parts of the world.
say their work raises considerable concerns about health impacts of consuming
high arsenic rice as a staple, particularly by people with relatively poor
nutritional status – perhaps as many as a few hundred million people. How
directly relevant the results are to people in the UK, with a generally lower
consumption of rice and better nutritional status, remains to be fully
determined but is an obvious focus for further research.
David Polya, who led the Manchester team in the University's School of Earth,
Atmospheric and Environmental Sciences, said: "Although concerns about
arsenic in rice have been raised for some time now, to our knowledge, this is
the first time a link between consumption of arsenic-bearing rice and genetic
damage has been demonstrated. As such, it vindicates increasing concerns
expressed by the European Food Safety Authority and others about the adequacy
of regulation of arsenic in rice.
the absence of contamination, rice is an easily stored food that provides
essential energy, vitamins and fibre to billions of people around the world,
but a small proportion of rice contains arsenic at concentrations at which we
have observed significant genetic damage in people who consume it as a staple
food. We hope that our work will encourage efforts to introduce regulatory
standards for arsenic in food, and particularly in rice, which are more
consistent and protective of human health."
Dr Ashok K
Giri, who led the Indian research team, added: "Although high arsenic in
rice is a potential threat to human health, there should not be any panic about
the consequences, particularly as the health risks arise from long-term chronic
exposure. We can avoid high arsenic rice by taking proper mitigation strategies
for rice cultivation; moreover, one CSIR institute in India has already
identified a number of Indian rice varieties which accumulate lower
concentrations of arsenic, so we can easily address future human health risks
with proper mitigation strategies Results of this study will not only help to
understand the toxic effects caused by this human carcinogen, but also these
results will help the scientists and regulatory authorities to design further
extensive research to set improved regulatory values for arsenic in rice,
particularly for those billions of people who consume 10 to 50% rice in their