(Reuters Health) - Insecticide foggers, also known as “bug bombs,” are still causing illnesses in the U.S., even after manufacturers were ordered to change the products’ labels to make them safer, researchers say.

In a 10-state study of illnesses and injuries related to so-called total release foggers, researchers found more than 3,200 incidents over roughly an eight-year period, for a rate of 27 per 10 million people per year. The illnesses included respiratory, gastrointestinal, cardiac, neurologic, and eye and skin problems.

“It is very important and helpful to spread the word that more comprehensive strategies are needed to reduce acute total release fogger-related illnesses,” said one of the authors, Dr. Walter Alarcon of the CDC’s National Institute for Occupational Safety and Health in Cincinnati, Ohio.

The Environmental Protection Agency required bug bombs to have improved instruction labels after 2012, with pictures to emphasize important actions users need to take, such as leaving the home for at least two hours and ventilating the area for an additional two hours.

The rate of illness related to bug bombs did not go down after product labels were changed. In fact, some types of incidents even increased, the study team notes in the Centers for Disease Control’s Morbidity and Mortality Weekly Report.

“The best precaution is to not have bugs in your home in the first place, which means depriving food, water and shelter from pests,” Alarcon told Reuters Health by email. “If these measures do not work and you need to use bug bombs, it is important that you read and follow the label instructions.”

Alarcon and colleagues used several health surveillance databases to see whether the relabeled changed the number, characteristics and severity of illnesses related to bug bombs between 2007-2015. In particular, they looked at data from pesticides programs and poison control centers in Texas, Florida, North Carolina, Michigan, Washington, California, Louisiana, New York, Oregon and Nebraska.

Among 3,222 illnesses, the most common symptoms were coughing, vomiting, nausea, respiratory pain and abdominal pain. About 5 percent of cases happened in children under age 5, and 14 percent occurred in adults over age 60.

“Exposure narratives from case reports suggested that many users did not follow or read label instructions,” Alarcon said.

People who didn’t leave their homes during the bug bomb deployment were most likely to report illness, and to have moderate or severe symptoms. Others had problems after re-entering their home early or being sprayed in the face or at close range during a nozzle malfunction or by pointing the nozzle in the wrong direction.

“Foggers are outdated residential pest control devices for several reasons,” said Dr. Alex Lu of the Harvard T.H. Chan School of Public Health in Boston, who wasn’t involved in the study.

“It is not very effective for some pests, such as bed bugs or cockroaches,” he told Reuters Health by email. “It definitely poses a great concern for human exposure to pesticides after use because residue is left on surfaces that people, especially toddlers and young children, come into contact later.”

A limitation of the study is that the poison control centers may not have data from people who had mild cases and didn’t report their experiences. Some of the cases may also be considered “false positives” because the symptoms may not be caused by foggers, the authors note. In addition, the study only includes data from 10 states and for three years after the new EPA label requirements were in force.

The study team recommends better public communication about the hazards and proper use of total release foggers, as well as a new design for the products that would prevent sudden, unexpected activation before residents can leave their homes.

“It’s very easy to misuse them or not follow the instructions properly,” Lu said. “Even I have a hard time following the exact instructions.”

SOURCE: bit.ly/2nRtp2n Morbidity and Mortality Weekly Report, online February 2, 2018.