1 November 2019

What Is and Isn’t Safe to Eat? Risk = Hazard x Exposure

Roberto Ramírez, MD

Public Affairs Manager
Andean Region
Bayer CropScience, Colombia

By Roberto Ramírez, M.D.

To most, “eating healthy” means consuming fruits and vegetables, drinking lots of water, eating protein and fiber, and exercising. And while all of these habits and foods are healthy, anything in excess can be harmful.

Cyanide, for example, is one of the most common and known types of poison. Less than a gram of it can kill a human being. But if I told you water can also be lethal; would you believe me? Well, indeed it can: 10 liters of water in a single intake have a 50 percent chance of leading to death since this dose dilutes the sodium and potassium present in the bloodstream, which could cause a heart attack. In 2008, Englishwoman Jacqueline Henson, a 40-year-old mother of five, made the headlines after dying in what was called a “tragic accident.” She had been on a water only diet for three weeks in order to lose weight.

We all know water is necessary for life, but when consumed in excess, it is not. This example allows me to explain something that is hard for doctors and scientists to communicate: zero risk doesn’t exist because there will always be a certain degree of exposure that could cause harm.

The responsible use of pesticides allows us to have nutritious, healthy and quality food, which can additionally help farmers have a good income and quality of life.

As established by Paracelsus in the 16th century: “All things are poisons, for there is nothing without poisonous qualities. It is only the dose which makes a thing poison.” There are many examples of this: an excess of vitamin D can cause cancer and more than three grams of salt per kilogram of weight can cause death.

Paracelsus’ quote can also be applied to pesticides, which often cause governments, organizations and people to worry. However, the responsible use of pesticides allows us to have nutritious, healthy and quality food, which can additionally help farmers have a good income and quality of life.

Case in point, the E. coli outbreak last Thanksgiving in the United States on romaine lettuce may not have occurred if pesticides were used. Authorities warned against consuming this type of lettuce due to contamination of unidentified origin.  As a doctor, I can tell you that this type of bacteria can be found on a crop through contamination with animal feces, such as those on organic crops that use uncontrolled compost mixtures to fertilize soil. Contrary to what many may think, when pesticides are used correctly and as directed on their labels, they can reduce these types of risks.

No one wants to consume hazardous doses of pesticides, which is why it is important to remember that the risk of these products is defined by the dose and exposure food crops have to them. The plain fact that a type of food has been exposed to a pesticide, doesn’t make it dangerous, nor unhealthy.

Food is a subject that I am passionate about. Every day I hear people saying that food isn’t safe to eat, but thanks to science – which has allowed us to better understand cellular processes – the modernization of the food industry and the thousands of tools we have to produce them, I can assure you we have never had safer food.

Roberto Ramírez, M.D. is public affairs manager, Andean, Central America and Caribbean  regions, for Bayer CropScience in Bogota, Colombia.

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    One response to “What Is and Isn’t Safe to Eat? Risk = Hazard x Exposure”

    1. Estimado Roberto,
      Congratulations for this very educational text. Very important to keep communicating science! Very important keep communicating safety concepts!

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