This 1990 American study https://www.ncbi.nlm.nih.gov/pmc/articles/PMC54831/ concludes:
We calculate that 99,99% (by weight) of the pesticides in the U.S. diet are chemicals that plants produce to defend themselves. Only 52 natural pesticides have been tested in high-dose animal cancer tests, and about half (27) are rodent carcinogens; these 27 are found in many common foods. We conclude that natural and synthetic chemicals are also likely to be positive in animal cancer tests. We also conclude that at low doses from most human exposures, the comparative dangers of synthetic pesticide residues are insignificant.
This one more recent Evaluation and refined perspectives of the cumulative risk resulting from dietary exposure to pesticide residues in the Danish population.
This study provides additional support to the evidence showing that the adverse health effects of chronic exposure to pesticide residues in the Danish population are very unlikely. The HI for pesticides for a Danish adult was comparable to that for alcohol for a person consuming the equivalent of a glass of wine every seven years.