Arsenic exists in various forms, with inorganic arseniccompounds that lack carbonbeing the most notorious for its toxicity. The World Health Organization has classified it as a confirmed carcinogen and identified it as the most significant chemical contaminant in drinking water worldwide. Inorganic arsenic is particularly harmful to humans due to its unstable nature, which facilitates interaction with other molecules, exacerbating exposure risks. Chronic exposure to inorganic arsenic has been associated with numerous health issues, including lung, bladder, and skin cancers, heart disease, diabetes, neurodevelopmental problems, and weakened immune systems.
Despite growing awareness of dietary exposure to arsenic, public health experts have long considered that the threat from contaminated groundwater poses a much greater risk. As a result, regulatory measures to mitigate arsenic exposure in food have been sluggish to develop. Existing standards adopted by entities like the European Union and China are often inconsistent and poorly enforced. In the United States, the Food and Drug Administration has set an action level of 100 parts per billion of inorganic arsenic in infant rice cereal, but this guideline lacks enforceable regulations for arsenic in rice or other food products.
Wang is advocating for urgent reforms. Although the current levels of inorganic arsenic found in rice conform to recommended standards in China, her study indicates that the incidences of bladder and lung cancer are likely to rise proportionally with exposure by 2050. Under a worst-case climate scenarioa scenario where global temperatures rise above 2 degrees Celsius (3.6 degrees Fahrenheit) and CO2 levels increase by an additional 200 parts per millionresearchers predict that inorganic arsenic levels in the studied rice varieties could surge by an astonishing 44 percent. This increase could result in more than half of the rice samples exceeding China's current limit of 200 parts per billion for inorganic arsenic in paddy rice, translating to an estimated 13.4 million cancers attributed to rice-related arsenic exposure.
Particularly vulnerable populations, such as infants and young children, are expected to bear the brunt of these health risks. The researchers indicated that babies might face disproportionately high risks from consuming rice cereals.
Were discussing a staple crop that sustains billions of people, commented Lewis Ziska, a plant biologist and co-author of the study who researches the intersections of climate change and public health at Columbia University. Considering that rising carbon dioxide levels and increasing temperatures can significantly influence arsenic levels in this staple food, the potential health consequences are, to put it mildly, enormous.
However, Ziska cautioned against an immediate halt to rice consumption. While the study revealed that inorganic arsenic levels in rice are higher than in many other plants, they still remain relatively low overall. Thus, the health implications largely depend on individual consumption patterns. For those who regularly consume rice multiple times a week, the impending health risks may be more pronounced, while those who eat it less frequently might not face significant health threats.
This disparity could exacerbate existing social and global inequalities, as rice has long been favored as a dietary staple due to its affordability. To combat the increasing health risks associated with arsenic, Ziska emphasized the importance of adaptation strategies for rice cultivation. These may include encouraging farmers to plant rice earlier in the season to avoid higher temperatures, adopting better soil management practices, and breeding rice plants that are less prone to arsenic accumulation.
Additionally, implementing water-saving irrigation techniques, such as the practice of alternate wetting and dryingwhere fields are flooded and then allowed to dry in cyclescould help reduce both arsenic exposure and the significant methane emissions produced by rice cultivation. Approximately 8 percent of global methane emissions from human activity are attributed to rice production, as flooded fields create ideal conditions for methane-emitting bacteria.
This is an area that may not seem as urgent as rising sea levels or extreme weather events, Ziska remarked. Yet, I assure you that the implications will be profound for humanity, given that rice is a dietary staple for billions.
This article originally appeared in Grist, a nonprofit independent media organization dedicated to highlighting climate solutions and advocating for a just future. To learn more, please visit
