npr.org

The recent outbreak of West Nile virus in the Dallas area has led to a new round of large-scale spraying for mosquitoes — a method of treating outbreaks that has generations of success, and even nostalgia, behind it.

Although the overall mosquito-killing strategy has changed little since the days when it was pioneered during construction of the Panama Canal a century ago, the chemicals used have become much safer for everything and everyone involved, save the mosquitoes, experts say.

Still, raining insecticides down from the sky has alarmed some residents of Dallas, where an outbreak of mosquito-borne West Nile has killed at least 10 people and sickened more than 200 others. On Wednesday, Dallas Mayor Mike Rawlings approved the first aerial spraying over the city in some 45 years.

The last time Dallas was the target of an “aerial application” of insecticide, malathion was used. The chemical was the subject of controversy in the 1980s when it was used to kill the Mediterranean fruit fly in California. It is considered generally safe for humans.