“The dirty dozen” – a list of fruits and vegetables supposedly carrying the highest amounts of pesticide residue published on the website of the Environmental Working Group – is actually quite misleading. The Journal of Toxicology recently published a dissection of the list done by food researchers, which put its claims into perspective.
Basically a reiteration of the test information available on the USDA’s Pesticide Data Program, the list then comes up with a ranking for each contaminated fruit based on the number and amount of different pesticides found on fruit samples.
What the list does not account for, however, is the highly-varying toxicity of different fruits.
The researchers first compared pesticide amounts found on listed fruits with industry and government standards for safe consumption listed as the “chronic reference dose.” The safe consumption levels refer to an amount of pesticide that would be safe for human consumption if consumed every day for life. It is also one hundred times less than the amount that experimental animals were able to consume with no effects. Thus, the “chronic reference dose” represents a very wide safety margin when it comes to pesticide consumption.
The researchers found that none of the “dirty dozen” fruits went above the chronic reference dose’s safe levels.
“All pesticide exposure estimates were well below established chronic reference doses (RfDs). Only one of the 120 exposure estimates exceeded 1% of the RfD (methamidophos on bell peppers at 2% of the RfD), and only seven exposure estimates (5.8%) exceeded 0.1% of the RfD. Three quarters of the pesticide/commodity combinations demonstrated exposure estimates below 0.01% of the RfD (corresponding to exposures one million times below chronic No Observable Adverse Effect Levels from animal toxicology studies), and 40.8% had exposure estimates below 0.001% of the RfD,” their report stated.
An alternative list also compiled by the Environmental Working Group, “the clean fifteen” – claiming to list the most pesticide-free fruits – was also scrutinized by the researchers. They found that the vegetable with the highest dose of pesticide residue, cauliflower (10% over RfD levels compared to other crops) somehow appeared on the “clean” list.
The uncomfortable truth is that even organic farms, promoted by groups like the EWG as a healthier alternative to supermarket produce, also use pesticides.
There is, perhaps surprisingly, a list of pesticides which are approved by the US government for use on organic-certified farms. It includes several toxic substances which go unregulated because they are not synthetic. Plant-based pesticides, as history has proven, can be just as harmful as synthetic ones. Even more startling, researchers cannot accurately compare the amount of pesticides found on organic and conventional produce since the USDA doesn’t even test for individual organic pesticides.
Organic produce farming indeed uses fewer synthetic pesticides in its growing, but the full picture is still unclear, at best.
Do not let these statistics – or lack thereof – dissuade you from eating fruits and vegetables. How should you ensure that you are consuming as little pesticide residue as possible? The best option available to date is to purchase from local farms that can be held accountable for their claims and methods.
In general, you should be aware that a government-certified organic label – while providing information about food irradiation, animal antibiotics, and certain fertilizers and pesticides – is not a complete story of pesticide residue.