Severe storms and floods can cause environmental and public health problems. Severe storms include thunderstorms, heavy rains, strong winds, hurricanes and cyclones, and storm surge. Catastrophic flooding can be caused by any of these severe storms or by tsunamis. Thunderstorms are local storms accompanied by rain, lightning, and thunder. A cyclone is a large-scale circulation of strong winds around a central core or "eye". A hurricane is a cyclone in the Western Hemisphere that starts in the tropics and has winds above 74 miles per hour. A tsunami is an ocean wave produced by an earthquake, landslide, or volcanic eruption. Tsunamis can travel across entire oceans and cause severe flooding when they make landfall. Storm surge is very high tides and waves, driven by strong hurricane winds, that flood coastal areas.

Severe storms and floods can create solid waste, debris, and polluted flood water which can contaminate drinking water, soil, and food with toxic chemicals. They can cause power failures, threaten above-ground and underground storage tanks, and make roads and bridges unsafe. Damaged or flooded septic systems or wastewater treatment facilities can result in raw sewage contaminating flood water. A flooded septic system can contaminate nearby drinking water sources. 

Severe storms and floods can cause drowning and injuries if people are caught in flood waters or hit by falling or flying objects. A tsunami can cause drowning and severe injuries if people are caught in the incoming wave or in the powerful suction of the water rushing back out to sea that follows. 

Evacuations may be necessary before a severe storm. A storm can damage homes and buildings, forcing people to seek shelter during and after the storm. If you leave your home, don’t return until you are told it is safe to do so. After a flood, electrical power, natural gas, and propane tanks can pose a risk of fire, electrocution, or explosions. Emergency generators can emit dangerously high levels of carbon monoxide and must be used or vented outside. After a flood, mold may grow on household materials and belongings that are wet. Mold can cause difficulty breathing, irritated eyes and skin, and other health problems. 

If polluted floodwaters linger after a storm, there’s the possibility of infection from wading in the flood waters or using the water for drinking and cooking. Flooding may also leave pools of water used for breeding by disease-transmitting mosquitoes. 

This description is based on the information found in the Web links listed with this topic.

Web Links from MedlinePlus (National Library of Medicine)
Coping with Disasters
Disaster Preparation and Recovery
Floods
Frostbite
Hazardous Waste
Hurricanes
Tornadoes
Tsunamis
Winter Weather Emergencies

More Links
Clinician Recommendations Regarding Return of Children to Areas Impacted by Flooding and/or Hurricanes (Pediatric Environmental Health Specialty Units) (PDF — 73.09 KB)
Disaster Assistance (DisasterAssistance.gov)
Flooding and Communicable Diseases Fact Sheet (World Health Organization)
Floods (Centers for Disease Control and Prevention)
Hurricane eMatrix (Occupational Safety and Health Administration)
Hurricanes and Other Tropical Storms (Centers for Disease Control and Prevention)
Hurricanes and Typhoons (National Library of Medicine)
Tornadoes (National Library of Medicine)
Tsunamis (Centers for Disease Control and Prevention)

Chemicals and Floods
Are these chemicals in MY community?
Acetone
Ammonia
Benzene
Chromium
Diesel
Formaldehyde
Gasoline
Lead
Mercury
Perchlorate
Perchloroethylene (PCE, PERC)
Pesticides
Phthalates
Polybrominated Diphenyl Ethers (PBDEs)
Polychlorinated Biphenyls (PCBs)
Solvents
Toluene
Volatile Organic Compounds (VOCs)

Last Updated: August 22, 2017