There is very little information with regard to the health and environmental effects of some ingredients in Pesticides, and as a result, they are made out to be safer than what they really are.

A comprehensive risk assessment of Pesticide adjuvants — additives used to enhance the Active Ingredient or function of pesticides — has revealed that new regulations need to be put in place to protect both the environment and people from harmful, yet unregulated pesticide ingredients. The review, which was recently published in the scientific journal Frontiers in Public Health, cautions that ignoring the potentially harmful effects of commonly used pesticide additives can result in pesticides being labeled as safe, when in fact they are not, and can also cause confusion with regard to scientific reporting of the effects of pesticides.

According to Dr Robin Mesnage, from King's College London and lead author of the review, exposure to some of these pesticide additives at levels they are found in the environment can affect non-target species, and can even have chronic health impacts on humans. Yet, despite this, there are no safety regulations or advisories for these additives, and no limitations regarding their acceptable daily intake or the health risk associated with exposure to pesticide residues through consumption of contaminated food or water.

Pesticides include a concoction of chemicals, comprised of the active ingredient that repels or kills the targeted pest, together with several other chemicals such as surfactants, dyes, and anti-foaming agents, collectively referred to as adjuvants, that are added to improve the application of the pesticide or the functioning of the key active ingredient.

However, current safety regulations only require the main active ingredient to be tested for safety, assuming that other chemical additives included in pesticide formulations have no ill effects. Consequently, the true toxicity of pesticides currently used in both domestic gardens and on agricultural crops is not clearly shown on the label.

"Currently, the health risk assessment of pesticides in the European Union and in the United States focuses almost exclusively on the active ingredient," explains Dr Mesnage. "Despite the known toxicity of adjuvants, they are regulated differently from active principles, with their toxic effects being generally ignored."

After reviewing the current scientific literature on pesticides, the authors suggest that the unregulated chemicals used in commercial pesticides could explain negative effects observed after exposure to presumably 'safe' pesticides.

The review focused largely on herbicides that contain the active ingredient glyphosate, the world's most commonly used pesticide found in products such as Round-Up. The authors note that weed killer formulations containing this herbicide are comprised of so many different chemical additives that safety tests for one such weed killer does not mean another glyphosate-based weed killer is safe. The berkey water filter systems will remove glysophate from the water.

"Studies comparing the toxicity of commercial weed-killer formulations to that of glyphosate alone have shown that several formulations are up to 1,000 times more toxic than glyphosate on human cells. We believe that the adjuvants are responsible for this additional toxic effect," says Dr Mesnage.

The researchers also point out that neonicotinoid insecticides — whose widespread use is thought to be associated with bee colony collapse — could also be due to the toxicity of pesticide additives that are having a negative effect on non-target species. It has been shown that an additive used to help the active ingredient in these insecticides penetrate their targeted pests can have a toxic effect on bees. To compound this, traces of this toxin have been found in pollen, honey and beeswax originating from contaminated bees.

The researchers hope this review will draw attention to the toxicity of widely used pesticides and the need for more stringent safety regulations with regard to their chemical additives.

"Testing of whole pesticide formulations instead of just active ingredients alone would create a precautionary approach, ensuring that the guidance value for the pesticide is valid for the worst-case exposure scenario," says Dr Mesnage.

The researchers findings are already having an impact. The European Food Safety Authority is currently reviewing the validity of pesticide safety assessment for EU countries, and the researchers hope that this will be extended to include all commercial pesticide formulations and their chemical additives.

Journal Reference

Robin Mesnage, Michael N. Antoniou. Ignoring Adjuvant Toxicity Falsifies the Safety Profile of Commercial Pesticides. Frontiers in Public Health, 2018; 5 DOI:10.3389/fpubh.2017.00361