July 2005
ToxTalk
The Pesticide Information Office is continually reviewing literature regarding agricultural toxicity, and that includes the chronic effects associated with farm communities. Certain activist organizations have recently begun promoting consideration of farm children as a recognizable population sub-group in hopes of, among other things, lowering tolerances for pesticides. They may want to be wary of using this group, because they could be healthier than non-farm children. Numerous studies have documented that exposure to bacterial endotoxin (from animal fecal material) suspended in the farm environment greatly reduces the incidence of hay fever, asthma, and atopy (allergic reactions with strong family tendencies) when children are exposed during the first five years of their lives. It has also been recently shown that this protection extends into young adulthood and may be resident for life. The underlying thought is that immunoglobulin E (IgE)-mediated processes for recognition of microbial products somehow regulate the resulting inflammatory responses through adaptive immunity.
There is some irony here because many are aware of illnesses and some deaths that have occurred with petting zoos (a source of endotoxin). In these cases, illness was linked to the presence of intact bacteria rather than endotoxin. So it appears while it is still advisable to wash hands after visiting the petting zoo, it may also be wise to spend a little time “down on the farm” with your children.
