What does the government do to ensure that pesticides used on food are safe?

Question

What does the government do to ensure that pesticides used on food are safe?

Answer 1

Pesticides are poisons used to kill insects which eat human food. Just after application, the food is inedible to both humans and insects. After some time, the pesticides either degrade or are rinced away by rain. The crops are harvested and washed again to remove any traces of pesticides. Periodically, farm produce is inspected for the levels of pesticides present. The material is analyzed chemically using instrumentation like Gas Chromatograps. If the pesticides are still present, they must be at levels deemed safe for human consumption.

Where I live, the permissable levels of pesticides in milk are about 0.3 ppm. Anything deemed lower than this can be reported as "trace" or "negative" and said to be safe to consume. If a violation happens, then the state decides what to do.

When pesticides rince off crops, they can enter rivers and lakes and accumulate in fish. Pesticides are organic compounds and accumulate in fatty tissue. Another major class of organic pollutants are chemicals called PCB's. PolyChlorinated Biphenyls were once used in many industrial products but are now illegal because they are toxic. Like DDT, they degrade very slowly, and it is not unusual for PCB's to show up in fish at concentrations up to 10 PPM in the extracted fat.

PCB's also show up in dairy products because of the way some states regulate silos. Silage is very acid and will quickly decompose the concrete walls of a silo used for cattle feed. Coatings protect the concrete, but older coatings contained PCB's. In this state, all the law requires is to paint over the old sealer with non-toxic paint instead of destroying the silo completely. This temporarily solves the problem until the paint cracks and peels, allowing PCB's to escape into the silage again.

If the milk from a certain farm becomes polluted with pesticides or PCB's it can be disposed of, but sometimes for economic reasons, it is mixed with uncontaminated milk until the levels are back below violation levels. The solution to polution is dilution when a lot of money gets involved. Fish  may live in water, but they can't be diluted of course. Since it will take centuries for the PCB's to degrade, the state simply issues a fish advisory stating the local fish are safe just so long as the fatty portions are not consumed.

Even organic produce is suspect. The products are grown without any agricultural chemicals of any kind, but this applies only to the current owner of the farm. Often the propertly was purchased at a discount because it was badly polluted. Traces of these chemicals then work their way into the "organic" produce. The problem is compounded because pesticides are not routinely checked in organic produce, simply because it is assumed they should not be present in the first place. Therefore it is much more likley to find pesticide traces in organic products than those from commercial farms, whose pesticide use is much more strictly monotored.

I live in Indiana. We have the strictest voting laws and the most unrestrictive environmental laws in the USA!

Answer 2

Generally the registrant of the pesticide is required to do a certain amount of testing to make sure that a pesticide is safe. A lot of this testing is based on human health studies, and honestly, that's probably where pesticides are the least likely to be toxic. HOWEVER (and there is a big however), some pesticides were registered with the EPA (in the US) decades ago when the requirements to register were less stringent. (Pesticides have to be registered with the EPA to be sold in the US, some states have more stringent requirements, such as California who has their own Department of Pesticide Regulation who also does a registration process.) When these pesticides have come up for re-registration, they've had their uses modified or canceled (that's what they call it) for safety's sake. This is kinda lame because unless a pesticide has notably caused a lot of problems or some group makes a big stinking deal about it, a pesticide can be harmful and that's that. It stinks in my opinion.

The government (and this depends on the state that you live in, if in the US) also sometimes tests for residues in the food we eat, but it's a small sample and not everything is tested. The acceptable levels of residues may or may not be totally protective of human health, but perhaps I'll be an optimist for once and assume that they are. I work with pesticides in water quality, and the numbers are lame and non-protective, if they are even there at ALL. And that is that.