How Are Pesticides Detected on Food?

Pesticides are an integral component of modern agriculture. With a ballooning global population and a rising demand for food, farmers must battle against all kinds of challenges, including climate change, extreme weather events and the proliferation of pests and blights. With that in mind, the responsible use of pesticides is key to cultivating enough produce for all.

At the same time, certain pesticides are toxic to human health and must not be ingested. Farmers are limited in the concentrations of pesticides to which they are allowed to subject their crops, while all food must be thoroughly washed before being sold and consumed to ensure that no pesticides remain in or on the item in question. But how are they detected?

Official regulation

The governing body in a particular country is responsible for setting so-called “tolerances”, which are the maximum residue of pesticide that is deemed safe on a crop. This figured is arrived at by using the latest techniques in food analysis and applying safety margins for what studies have shown to be harmless for human health if ingested on a daily basis over a lifetime.

The relevant authority (such as the Food and Drug Administration – or FDA – in the USA, for example) is then responsible for testing produce on a regular basis and enforcing their own thresholds. If a supplier is found to have exceeded the limits, their produce must be recalled and the company could be at risk of financial penalisation.

Criticisms of the current system

However, some environmentalists have raised concerns over the existing system. For one thing, they do not believe that the tolerances defined by the regulatory bodies go far enough in their analysis of the effects of the human body and as such do not err on the side of caution. Moreover, they complain that testing regimes are set up to target those who have transgressed in the past rather than subject random samples to spot checks, thus creating the possibility that plenty of contaminated produce could sneak under the radar.

Finally, there are also concerns that some pesticides are not even being detected at all. Glyphosate is a notable case in point. While current techniques of quantification of glyphosate, glufosinate and AMPA in foodstuffs have advanced in recent years, glyphosate was not even included in the list of tested substances until 2017. Given that it’s the most widely used pesticide in the world, that’s quite an oversight.

Empowering the people

A novel invention that could potentially solve such problems has been developed by a University of Texas professor named Shalini Prasad. Consisting of a handheld device and small swabs, the detector works by swabbing a piece of produce and then inserting the swab into the device. Within 30 seconds, the device is capable of detecting the levels of up to 24 chemicals and will indicate whether they are safe or not via a green or red light.

The device is aimed at growers, organic certification providers and consumers themselves. Although the detector only verifies residue levels on the surfaces being swabbed, it is far more sensitive than the technology used in laboratories and can deliver quick, efficient and cost-effective results. Moreover, the fact that it can be used by everyday consumers with no specialist knowledge could be a vital step in empowering people to detect pesticide levels in their food and look after their own health.