Buzz-zzz

Mosquito Heaven

Zzzzzzz … swat, slap … zzzzzz. I haven't had so much trouble with mosquitoes since I lived in Minnesota. There, mosquitoes threaten to carry away your first born if you don't hand over a pint of blood; as a result of this training, I've found the bothersome bugs to be a non-problem here in Oregon. Until this year, that is.

Apparently one of this diverse family of bloodsuckers is called a floodwater mosquito, and she can lay eggs that won't hatch for years until sated by a drink of water. That drink was well supplied by the late spring rains that had Portlanders whining so recently.

I was born into a post World War II era excited about aggressive chemical responses to problems like mosquitoes. DDT had been in wide use for malaria control during the war, and it received a plum civilian post in the US agriculture industry. Folks one to two decades older than I, report playing games chasing pesticide trucks, seeing who could stay in the cloud of bug spray the longest.

DDT is considered a carcinogen. Studies in humans have implicated this pesticide in cancers of the liver, pancreas, and breast, with some evidence that it causes leukemia, lymphoma, and testicular cancers. A neurotoxin, it is also implicated in developmental problems in children, reproductive problems for men and women, low birth weights and infant deaths, and endocrine disruption, including thyroid disorders. For a long time, the relationship between DDT and breast cancer was unclear. Some women with exposure had high incidences of breast cancer, some did not. In 2007, a well-designed study showed that timing of exposure is critical – women exposed to DDT before puberty had a five-fold increase in breast cancer incidence over women born at least 14 years before the widespread agricultural use of DDT burst onto the American scene in the early 1940's.

DDT is a persistent organic pollutant that collects in soil and is magnified in the food chain. Though it was banned for use in the US in 1972 it is still in use around the world; in 2005 a study showed that all human blood samples tested in the US still show residues of DDT.

The punch line?

Mosquitoes (and other pests) effectively develop resistance. So much so that use at low doses can actually increase deaths from malaria by a rebound effect. DDT has been abandoned by the World Health Organization as a method of controlling the disease.

I'm happy to pull out my citronella-soybean-peppermint-cedar-lemongrass-geranium insect repellent. This morning I covered my legs in the fine pungent spray and gave a few quick squirts to the dogs. We were all fine, and as far as anyone knows, we did not increase our risk of cancer by repelling the bugs.