Last month, we examined what employers can do to help protect workers from the effects of heat and the risk of tick-borne illnesses. This month, we take a look at mosquitoes, which can transmit a number of dangerous diseases including Zika, West Nile and chikungunya.
Construction sites can be prime locations for mosquito breeding. That’s because tire ruts, building materials and equipment can all collect water. Encouraging workers to use insect repellent with DEET (on skin or clothing) or permethrin (on clothing and gear) and to wear light-colored clothing is important, but more needs to be done to reduce the risk for mosquito bites.
“Diseases like Zika and West Nile show that mosquitoes can be more than annoying seasonal pests,” says LIUNA General Secretary-Treasurer and LHSFNA Labor Co-Chairman Armand E. Sabitoni. “They can pose a serious threat to worker health, particularly for our members and other construction workers who spend most of their days outdoors. To keep all workers safe on the job, contractors should implement mosquito controls that make construction sites and other job sites less attractive to these insects.”

LIUNA General Secretary-Treasurer and LHSFNA Labor Co-Chairman Armand E. Sabitoni
What Can Employers Do
Mosquitoes can hatch eggs in any puddle or even a bottle cap full of water in just four days. Eliminating standing water is the most effective way to reduce mosquitoes at a construction site. OSHA recommends the following steps:
- Avoid leaving containers that can accumulate water in an uncovered or upright position. This includes wheelbarrows, drums, buckets, cans, tarps and other containers.
- Drain or pump out collected water from newly constructed swimming pools, clogged rain gutters and ditches.
- Properly store any open containers in the work area, such as buckets and cans that are not being used.
- Create holes to drain water from containers that cannot be thrown out.
- Routinely remove garbage and other debris.
- Fill in potholes and other areas where water is likely to accumulate.
- Use aeration, wherever possible, as a way to prevent mosquitoes from laying eggs in ponds and other bodies of standing water. Consider the use of mosquito dunks, which are small doughnut-shaped blocks that dissolve slowly in water and contain bacillus thuringiensis israelensis (BTi), a naturally occurring bacterium that kills mosquito larvae but is non-toxic to animals and fish.
Contractors may also want to consider placing high-capacity fans near work crews, which can make it difficult for mosquitoes to land and bite. In extreme situations, contractors may also want to check with local authorities to see if environmental spraying is allowed.
The LHSFNA’s Health Alert on West Nile virus contains additional information for protecting against all mosquito-borne illnesses. LIUNA signatory contractors can order this and other materials by going to www.lhsfna.org and clicking on Publications.
A Growing Menace
Mosquitoes, ticks and fleas are increasingly threatening the health of workers and their families. In the U.S. alone, the number of Americans sickened by diseases linked to bites from these three insects tripled between 2004-2016 to more than 640,000 cases. Nine new germs spread by mosquitoes and ticks were either discovered or introduced to the U.S. during this time period, including Zika and the Heartland virus.
According to the Centers for Disease Control and Prevention (CDC), the U.S. is not fully prepared to fight these and other vector-borne illnesses. “[W]e don’t know what will threaten Americans next,” said CDC Director Robert R. Redfield, M.D. “Our nation’s first lines of defense are state and local health departments and vector control organizations, and we must continue to enhance our investment in their ability to fight against these diseases.”
[Janet Lubman Rathner]