Here is a pretty thorough discussion: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3138025

The authors do mention what was mentioned below, just because pesticides are not synthetic doesn't mean they are necessarily safer:

One such alternative is so called “natural pesticides” that are not synthetically produced, but are derived from nature such as botanicals pesticides (pyrethrum, limonene, and many others), microbial/biological agents (microbes, parasites) and inorganic minerals (boric acid, limestone, diatomaceous earth). These solutions are generally assumed to be less toxic for human health than synthetic pesticides and could represent an interesting alternative. But their usefulness is actually questionable because some such pesticides are not potent enough to control pests but at the same time do exhibit adverse effects for human health (i.e. “natural pyrethroids”).

Another study discusses how exposure to a chemical called Atrazine (ATZ) causes mitochondrial dysfunction & insulin resistance: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2664469

ATZ treatments led to weight gain

ATZ increased visceral fat and intracellular fat content

ATZ treatment worsened insulin levels and HOMA-IR values

ATZ induced insulin resistance

ATZ changed the ultrastructure of mitochondria

ATZ exposure decreased energy metabolism

ATZ impairs mitochondrial OXHPOS through direct action

ATZ treatment blocked the insulin-Akt signaling pathway