Rice tends to attract a lot of nutrients that are present in the environment. Unfortunately this also goes for some unwanted elements. Rice absorbs arsenic that may naturally or unnaturally be present in the environment. As the nutrients, including any arsenic, tend to be absorbed more in the bran layer, brown rice is more strongly affected.
Firstly, lets realize, not all rice contains arsenic! Arsenic may be present only if it a) occurs naturally in the soil, b) has been artificially added to the soil, and /or c) is present in ground or irrigation water.
Organic and Inorganic Arsenic
Arsenic occurs in two different types of chemical structures, organic and inorganic arsenic. Note that these two chemical structures are not related to any farming process. So, organically grown food may or may not contain organic or inorganic arsenic.
Organic arsenic is bonded to carbon and is not easily absorbed by the body. This is the main reason why it is not very toxic and is not known to be a carcinogen.
Inorganic arsenic is not bonded to carbon and as a result is easily absorbed by the body, in the intestines, the lungs and the skin. It is highly toxic and is a confirmed human carcinogen.
When publications mention arsenic only, it is not clear which of the two chemical structures they are talking about, unless the immediate context clarifies it. When total arsenic is mentioned, it refers to both types together; yet the total is not useful in determining toxicity and carcinogenicity; the breakdown of total arsenic in the amount of organic arsenic and inorganic arsenic is very useful.
Arsenic in Food
Both organic and inorganic arsenic can occur naturally in air, soil and water, depending on location. When present in the environment it may find its way into seafood, fruit, fruit juices, vegetables, grains, other foods and drinking water.
Inorganic Arsenic in Food
Inorganic arsenic, the highly toxic and human carcinogenic type of arsenic, is also a significant man-made pollutant. It is created as a by-product of mining, smelting non-ferrous metals, and burning fossil fuels. It is also put to agricultural use as a component in pesticides, insecticides, fungicides and wood treatment.
Additionally, for the United States (USA) significant use of inorganic arsenic occurred with pesticides in cotton fields, some of which were later turned into crop fields. In Bangladesh it has been a major health and sociocultural problem with natural contamination of deep-well water affecting drinking water, rice, vegetables and other food; the contamination in Bangladesh began to occur mainly after aid organizations sought to alleviate chronic water shortages in villages by supporting the construction of deep wells.
In the EU and the US the agricultural use of inorganic arsenic has been banned since 2004. Much of the inorganic arsenic is still present in the soil, ground water, and arsenic (CCA) treated wood. In a number of countries such use continues.
Organic Arsenic in Food
Organic arsenic has been used as an additive in poultry and pig feed, as it was discovered that adding arsenic to animal food spurs animal weight increase, improves feed efficiency, fends off disease, makes meat look pinker and fresher in the supermarket, and most importantly, boosts corporate shareholder profit.
In the EU this practice was banned in 1999, in the US in 2013 for the feed additive 3-Nitro/Roxarsone, and in 2015 for the feed additive Nitarzone.
These bans were implemented as it became clear that:
- Some of the organic arsenic fed to chickens transformed into inorganic arsenic, that is highly toxic and known human carcinogenic arsenic
- The arsenic fed to chickens was not - as initially assumed - all defecated, but also remained in the meat that was consumed, combined with:
- Defecation from chickens and pigs - that is poultry and pig manure - is routinely used as agricultural fertilizer for all sorts of crops, including rice.
So after the inorganic arsenic was banned as a pesticide, organic arsenic was used as an animal food additive, some turning into inorganic toxic and carcinogenic arsenic, with both forms artificially going into fruits, fruit juices, vegetables, grains, ground, river and sea water in the form of agricultural fertilizer. So, if the arsenic did not get into consumers (that is us all) one way, it still got there the other way.
Lingering inorganic arsenic from industrial pollution, use as agricultural pesticides, animal food additives, and chicken /pig manure fertilizer still now affect some areas more strongly than others. Plus there are some countries and areas where the contamination marches on.
Rice absorbs more elements, that is nutrients and contamination, from the environment when compared with other crops. A larger portion of these elements are absorbed in the bran.
Contamination may occur anywhere where arsenic is present, while the most notable and studied locations for inorganic arsenic contamination appear to be Bangladesh and West Bengal, India, with inorganic arsenic naturally present in groundwater, and the US with inorganic arsenic present in soil from use of pesticides and fertilizer - while other locations with similar practices are likely to be similarly affected.
The milling process that creates white, polished rice leaves behind virtual mountains of rice bran. The nutritious bran is highly coveted by industrial food processors looking for nourishing ingredients and additives. When food processors concentrate rice bran or whole rice containing arsenic into specialized rice products (such as rice baby food, rice bran, rice cereals, rice crackers, rice milk, brown rice syrup) it is likely to result in high arsenic levels in these processed products. Given the same rice, processed concentrated rice products are therefore more likely to show higher arsenic levels than simple kitchen rice.
Where organic arsenic occurs naturally in soil and/or water it is not known to be toxic or carcinogenic, though wisely some authorities have established limits for total arsenic in food and drinking water.
Rice will not accumulate arsenic when it is not present in the environment.
Fortunately there are lots of environments where arsenic is not present. So yes, you can buy arsenic-free rice: Know your rice's origin. We are just one small example.
When viewing sources and articles on "arsenic in rice", consider the described location, the authors, the point of view, date and underlying sources.
For example, the top result for internet searches on arsenic in rice is: https://www.healthline.com/nutrition/arsenic-in-rice. Its heading "Why Is Arsenic Found in Rice?" states:
Paddy rice is particularly susceptible to arsenic contamination, for three reasons:
- It is grown in flooded fields (paddy fields) that require high quantities of irrigation water. In many areas, this irrigation water is contaminated with arsenic (22).
- Arsenic may accumulate in the soil of paddy fields, worsening the problem (23).
- Rice absorbs more arsenic from water and soil compared to other common food crops (8).
Using contaminated water for cooking is another concern, because rice grains easily absorb arsenic from cooking water when they are boiled (24, 25).
1. Paddy rice is the rice growing in the field. All rice grows in the field. There is nothing "particular" about it. But certainly not all paddy rice is affected.
2. It makes sense to have a look at these sources: 22, 23, 24, 25. The sources refer to the occurrence of inorganic arsenic naturally present in the ground water in known arsenic hotspots Bangladesh and nearby West Bengal, only. The authors subsequently, without further reason or indication, generalize their findings for South Asia, then Southeast Asia and finally all of Asia. The Healthline article then formulates it as "many areas" having arsenic contaminated irrigation water - leaving a quick reader to extrapolate it to "almost everywhere".
3. The fact is that there are certain locations known to be contaminated. There are also many areas that are not.
Sources for Organic and Inorganic Arsenic:
Sources for Inorganic Arsenic in Food:
- https://en.wikipedia.org/wiki/Roxarsone /Nitarsone
Note: The above information is based on nutrition research conducted by published professionals, specialists, and our own observations. Not all of the sources on this subject provide the same details. Consult with your friendly nutrition or health professional for a final, authoritative opinion.