In late January, the European Food Safety Authority (EFSA) concluded that there is significant concern regarding the health implications of arsenic in food after evaluating the risks associated with exposure to this contaminant through the diet. This assertion seemingly validates the fears of many individuals who, out of concern for arsenic, rinse rice before cooking it or discard the cooking water. However, before jumping to conclusions, it is crucial to delve into some details.

The Nature of the Concern

It’s important to clarify that we are not facing a food alert, which occurs when the contamination of a circulating food poses an imminent risk to health. Instead, this is a risk assessment conducted periodically to understand the current situation, considering the latest scientific knowledge and consumption habits. This enables the implementation of measures aimed at protecting public health if necessary.

Why Arsenic Ends Up in Food?

Arsenic is a common element in the Earth’s crust, widely distributed in the environment due to both natural sources (such as volcanic emissions, forest fires, mineral and rock erosion, etc.) and human activity (emissions from mining or metallurgical industries, insecticides, herbicides, etc.).

This means that many foods are susceptible to contamination with this chemical element and its compounds, although not all are equally concerning. For example, fish commonly contain organic forms of arsenic (such as arsenobetaine), which are less worrying than inorganic forms, which are much more toxic. That’s why the latest EFSA report focused on evaluating inorganic arsenic. These are absorbed from the soil by some plants like rice. In fact, the foods that contribute the most to human exposure to arsenic are rice and cereals, as well as products made from them; and it can also be present in drinking water.

Health Effects

Known as a potent poison since ancient times and more recently used as a pesticide, inorganic arsenic is present in much smaller doses in contaminated water and food. Nevertheless, even in such small quantities, it can increase the risk of various types of cancer, especially skin, bladder, or lung cancer, but also kidney, liver, and prostate cancer. Additionally, it can cause other adverse effects such as skin lesions, neurotoxicity, cardiovascular diseases, abnormal glucose metabolism, or diabetes, among others.

It is a genotoxic and carcinogenic compound, so any amount could potentially be dangerous to health. However, the dose and level of exposure matter: generally, the higher the dose and the more exposed we are, the more likely we are to experience adverse effects. This can be easily understood with the example of tobacco: when we inhale its smoke, we are also exposed to genotoxic compounds, so any amount has the potential to cause adverse effects, such as developing lung cancer. But it is very unlikely to happen with just one cigarette because the dose and level of exposure influence it: the more we smoke, the more likely we are to develop that disease.

Which Foods to Avoid?

The fact that water, rice, cereals, and products made from them contribute the most to dietary exposure to arsenic does not mean that we should avoid consuming them. Nor does it seem necessary to take extraordinary measures at the household level. This has not been specified in the EFSA report, which focuses solely on assessing the risk of arsenic, but it seems to be inferred from the data for the Spanish population. The same can be said if we consult the information published by the Spanish Agency for Food Safety and Nutrition (AESAN), which can be summarized in three points:

  1. Cereals are an important source of complex carbohydrates which, when combined with other foods, have a positive effect on health. Therefore, it recommends consuming cereals (wheat, corn, rice, oats, etc.), preferably whole grains, in an amount of between three and six servings per day, depending on energy needs.
  2. Water is the beverage of choice in a healthy diet, and the level of arsenic is generally very low.
  3. It is recommended to avoid consuming hiziki seaweed due to its high content of inorganic arsenic.

To Wash or Not to Wash

To address the doubts and concerns raised by the presence of arsenic in the diet, we can clarify some important details:

  1. Not all rice varieties are likely to contain the same amount of arsenic. Generally, levels are higher in brown rice than in conventional rice (around 1.7 times higher) because this compound accumulates in the bran.
  2. The origin also matters. There are countries like India and Bangladesh where the accumulation of inorganic arsenic in rice is higher, mainly due to contamination of irrigation water. In any case, all rice marketed in the European Union must comply with the maximum limits established by European legislation, regardless of its origin.
  3. A simple measure to reduce arsenic exposure levels is to follow a varied diet, alternating different types of cereals. It does not seem like a good idea to consume rice daily, especially if it is whole grain. This is of particular interest to certain population groups where exposure levels may be higher, such as young children or people with gluten-related disorders like celiac disease, as their diet sometimes predominates with rice-based products such as beverages, pasta, or cakes. Instead of consuming these products every day, it might be better to try to alternate them with other suitable cereals, such as corn, depending on the case.

Rinsing rice thoroughly (e.g., six rinses) before cooking it could remove between 10% and 30% of arsenic, while cooking rice in ample water (ratio 1:6) and discarding this water at the end could remove around 30-45% of arsenic. However, the results depend on different factors, such as the variety or type of rice. Therefore, while some research shows that both actions lead to a reduction of up to 57% of arsenic, other studies (such as the one mentioned by AESAN in its recommendations) only achieve a reduction of 11%. Moreover, it should be considered that these practices can also reduce the nutrient content of rice.

Are We Exposed to Dangerous Amounts?

To assess the safety of arsenic, the European Food Safety Authority (EFSA) has considered the risk of skin cancer because it is one of the most concerning adverse effects and because it is the most conservative approach, as it also protects against other adverse effects associated with this contaminant. With this new, more conservative reference compared to its previous evaluation in 2009, it has concluded that levels of arsenic exposure through the diet are a cause for concern in average consumers and, especially, in heavy consumers: for example, this would mean that a person who eats rice daily could have a 5% (or more) increased risk of developing skin cancer compared to another unexposed person.

However, it is important to consider that the level of arsenic exposure in the Spanish population is lower than the European average in all age ranges studied, as indicated by the Spanish agency AESAN. This means that the likelihood of experiencing adverse effects such as the one mentioned above is lower, so the situation is less concerning than for the population of other countries.

Furthermore, it should be noted that in younger population groups (especially children up to 10 years old), exposure levels are higher than in adults due to their lower body weight. From this, one might think that they are at a higher risk. However,

according to EFSA, this is not necessarily the case because the adverse effects of arsenic result from long-term exposure, and most epidemiological studies are conducted on adults who would have also had higher dietary exposure during their early years of life. Therefore, it is concluded that children are covered by this risk characterization.

Measures Taken

In the field of food production, measures have been implemented for years at all stages to try to reduce the presence of arsenic; for example, controls are carried out on irrigation water.

Analyses are also conducted on drinking water and certain foods to ensure that they comply with the maximum limits of arsenic established by legislation. Some of these limits were first set in 2015 for rice and derived products; and subsequently, in 2023, they were extended to other foods and made more restrictive, in line with advances in scientific knowledge.

Now, with the data obtained from the new EFSA report and pending the evaluation of the toxicity of organic arsenic and total arsenic (the combination of organic and inorganic) by this European agency in the coming months, it is very likely that measures will be taken to further reduce the population’s exposure to this substance. This may involve even stricter reduction of maximum permitted limits in certain foods, or perhaps offering consumption recommendations for the most exposed population groups.


In conclusion, while arsenic contamination in food is a concerning issue, it’s important to approach it with a nuanced understanding. While there are potential risks associated with arsenic exposure, particularly in heavy consumers, current measures and recommendations are in place to mitigate these risks. By staying informed and following best practices, such as maintaining a varied diet and adopting appropriate cooking techniques, individuals can help minimize their exposure to arsenic and safeguard their health.