Whenever the Chesco Health Department plans a so-called “spraying event,” the public needs to observe to be sure that applicable procedures are scrupulously followed and that adverse effects are as limited as possible. In 2017, the Health Department agreed to give 48 hours notice before spraying (it was previously 24 hours). Even so, we find that most people in the spray area do not receive the information and that many municipalities do not take responsibility for relaying it to their citizens.

We encourage you to Sign up for the Health Department mailing list so you will get the maximum warning. But don’t count on this alone to find out.

Anyone in a spray area, please try to observe (without exposing yourself directly to spray) and let us know:

• The releases say: “After exhausting all other available mosquito control strategies…” Do you know of strategies taken by the Health Department in your locality, such as working with the municipal government to educate residents, larviciding suspect bodies of standing water, or alerting property owners whose properties may be violating the Health Department’s regulation against allowing mosquitoes to breed in standing water?

• Were adequate warnings posted on affected streets so residents and visitors will know to stay out of the way of the spray and take protective measures, such as closing windows, turning off wall air conditioners, and bringing children inside? If so, how long in advance?

• Did you observe people who were not aware of the recommended precautions (such as joggers entering the area, students returning from class, people returning from shopping or jobs, etc., during or right after spraying)?

• Was there a lead truck in front of the spray truck and did it use a loud speaker to warn any people outdoors to leave the immediate vicinity or go indoors?

• Did the truck spray more than once in any street or on any area? Does it crisscross any area, thus delivering an extra dose to some addresses?

• Was the spray shut off as the truck approached a stream or body of water and if so, how many feet away on either side?

• In the days after spraying, what difference do you notice in the number of mosquitoes and other insects such as honey bees and dragonflies? Please try to video or photograph any evidence.

• Did you notice any effect, either immediate or after a few days, on pets, frogs, birds, bees, fish, or bats? Please try to video or photograph any evidence.

• How long did it take for the adult mosquito population to get back to about what it was before?

DSM needs you to help protect people and the environment and to let public officials know what you think.

Please also note these precautionary measures, which we base on extensive readings:

Spraying is always supposed to occur in the evening because bees are less active then and, if they know what is good for them, return to their hives (for what happens when spray is not scheduled properly see here). Beekeepers who have hives in the spray area need to take protective measures, as just one bee bringing pesticide back to the hive can be disastrous.

During the spraying (and ideally till the next day) residents should shut windows and close off all ways that outside air can enter their house (such as wall air conditioners unless you can set them securely to recycle indoor air). Pets should be brought inside, as they can be sensitive to pesticides. Remove children’s toys that are outdoors, any outdoor furniture, and clothes from outdoor clotheslines. The next day any furniture and outdoor play equipment should be washed off with soap and water before anyone comes in contact with it.

People who have a high level of chemical sensitivity may wish to plan an absence overnight or longer. To sign up for the Pesticide Hypersensitivity Registry (which gives you notification of not only County spraying but also commercial spraying in your vicinity), see here.