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Abstract A novel approach is developed to establish safety levels for organophosphate pesticides residues present in 80 fruit, vegetable, and nut commodities. These levels, known as Pesticide Safety Levels (PSL), represent the concentration of the organophosphate pesticide residue that would be required to cause daily exposure of the highest-consuming population subgroup at the 95th percentile of consumption (based upon US food consumption estimates) to reach the adjusted acute reference dose of the pesticide. A total of 4,320 PSLs were developed for 54 organophosphate pesticides on the 80 commodities. Comparisons of PSLs and tolerances and/or MRLs, when available, indicated that only a small percentage of PSLs were lower than or equal to regulatory levels (1.9% below/equal to tolerance levels and 2.3% below/equal to Codex MRLs). In the pesticide/commodity combinations where PSLs were below tolerances and/or MRLs, monitoring results indicated that the maximum residues of organophosphate pesticides on the commodities were far below both the PSL and tolerance/MRL values. In most cases, PSLs were much higher than existing tolerances and/or MRLs. PSLs were at least 100 times higher than tolerances in 50.1% of the comparisons and at least 100 times higher than MRLs 64.1% of the time. PSLs were at least ten times higher than tolerances 75.8% of the time and at least ten times higher than MRLs 82.8% of the time. PSLs serve a useful role in determining the health significance, if any, in the event that residues of organophosphate pesticides exceed existing tolerances and/or MRLs as well as in cases where residues of organophosphate pesticides are detected on commodities for which no tolerance or MRL has been established. PSLs can also be used to customize pesticide residue monitoring programs to focus more on consumer safety than on good agricultural practices.

Vitamin A (VA) deficiency causes disability and mortality. Cassava can be crossbred to improve its β-carotene (BC) content; typical white cassava contains negligible amounts of BC. However, cassava contains cyanide and its continued consumption may lead to chronic disability. Our objective was to estimate the risk–benefit of consuming BC-enhanced cassava to increase VA intake. A total of ten American women were fed white and BC-enhanced cassava. BC and cyanide data from the feeding study were combined with African cassava consumption data to model the potential daily BC, VA and cyanide intakes of African women. If BC-enhanced cassava replaced white cassava in the diets, it could theoretically meet recommended VA intakes for the following percentages of individuals from six African countries that consume cassava as a staple crop: Angola (95 %), Central African Republic (95 %), Congo (about 100 %), Ghana (99 %), Mozambique (99 %) and Nigeria (92 %). Cyanide intake after minimal preparation of cassava could be thirteen to thirty-two times the reference dose (RfD), a toxicological exposure reference, but could be completely removed by extensive soaking. This study demonstrates that consumption of BC-enhanced cassava, processed to maintain BC and remove cyanide, theoretically increases VA intakes for African populations and other areas of the world where cassava is a staple crop.

Probabilistic techniques were used to characterize dietary exposure of consumers to pesticides found in twelve commodities implicated as having the greatest potential for pesticide residue contamination by a United States-based environmental advocacy group. Estimates of exposures were derived for the ten most frequently detected pesticide residues on each of the twelve commodities based upon residue findings from the United States Department of Agriculture's Pesticide Data Program. 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 percent) 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. It is concluded that (1) exposures to the most commonly detected pesticides on the twelve commodities pose negligible risks to consumers, (2) substitution of organic forms of the twelve commodities for conventional forms does not result in any appreciable reduction of consumer risks, and (3) the methodology used by the environmental advocacy group to rank commodities with respect to pesticide risks lacks scientific credibility.

Allowable levels for pesticide residues in foods, known as tolerances in the US and as maximum residue limits (MRLs) in much of the world, are widely yet inappropriately perceived as levels of safety concern. A novel approach to develop scientifically defensible levels of safety concern is presented and an example to determine acute and chronic pesticide food safety standard (PFSS) levels for the fungicide captan on strawberries is provided. Using this approach, the chronic PFSS level for captan on strawberries was determined to be 2 000 mg kg−1 and the acute PFSS level was determined to be 250 mg kg−1. Both levels are far above the existing tolerance and MRLs that commonly range from 3 to 20 mg kg−1, and provide evidence that captan residues detected at levels greater than the tolerance or MRLs are not of acute or chronic health concern even though they represent violative residues. The benefits of developing the PFSS approach to serve as a companion to existing tolerances/MRLs include a greater understanding concerning the health significance, if any, from exposure to violative pesticide residues. In addition, the PFSS approach can be universally applied to all potential pesticide residues on all food commodities, can be modified by specific jurisdictions to take into account differences in food consumption practices, and can help prioritize food residue monitoring by identifying the pesticide/commodity combinations of the greatest potential food safety concern and guiding development of field level analytical methods to detect pesticide residues on prioritized pesticide/commodity combinations.