Responding to Environmental Health Threats Following Hurricanes

November 21, 2022 | Emma Carlson, Nicholas Porter

Empty room that is in the drying stages after a floodNatural disasters, including hurricanes, can cause extreme damage to community infrastructure and threaten the public’s health. As recently as early November, Hurricane Nicole made landfall on the east coast of Florida. In the days and weeks after a hurricane, there are often myriad environmental health hazards and public health concerns that continue to impact the affected communities. For example, floodwaters left after hurricanes can contaminate food, contain hazardous chemicals, contribute to mold growth indoors, and hide other hazards like damaged power lines.

State and territorial health agencies, in close collaboration with local health agencies and partner organizations, are on the front lines in responding to and mitigating post-disaster environmental health hazards. Agency leadership need to ensure they are equipped to respond to these powerful storms by integrating climate readiness into different public health programs ranging from food safety to zoonotic diseases.

ASTHO heard from members from the North Carolina Department of Health and Human Services NCDHHS, South Carolina Department of Health and Environmental Control (SCDHEC) , and Texas Department of State Health Services (DSHS) to learn more about their experiences of post-hurricane environmental health issues, as well as advice and best practices for responding to these challenges.

Post-Hurricane Environmental Health Issues


Following flooding events and inundation of buildings, wet conditions can facilitate the growth of mold indoors. Individuals have 24-48 hours to dry out their residences following flooding. Otherwise, it’s very likely that mold has begun to take hold indoors. Mold can contribute to several negative health outcomes (e.g., asthma exacerbation) and more serious issues for immunocompromised individuals. The linked guide above outlines steps homeowners and renters can take to remediate indoor mold growth on their own. However, professionals should lend a hand for more complicated jobs.


Carbon Monoxide Poisoning

Using gasoline, propane, natural gas, or charcoal burning devices in enclosed spaces can lead to carbon monoxide (CO) poisoning. Generators and portable stoves fall into this category and are commonly used following a hurricane. CO is an odorless, colorless, and tasteless gas produced when burning fuel, and it can rapidly build up when fuel-burning devices are operated indoors.

Common CO poisoning symptoms include headache, weakness, dizziness, chest pain, and nausea. Higher exposures can lead to death. NCDHHS recommends that generators and other CO-emitting devices be used outdoors and placed at least 20 feet from openings in homes and buildings (e.g., doors, windows, vents).


Texas Department of State Health Services

CO and mold exposure concerns are among the most common issues DSHS addresses after a hurricane. Similar issues include health-related concerns regarding exposures to chemicals after spills/leaks, cleaning products, hazardous debris, and contaminated drinking water. Actions that DSHS takes to address these issues include:

Track environmental exposure data and health concerns

DSHS uses data from the Texas Poison Center Network and Syndromic Surveillance System to track exposure data and health concerns, which helps inform the need for additional investigations, health advisories, and the development of outreach materials.

Develop and maintain relationships with internal and external partners

DSHS utilizes partnerships within the agency (e.g., between environmental health and emergency preparedness and response staff) and outside the agency (e.g., local health departments, Texas Commission on Environmental Quality, community organizations) to facilitate resource sharing, ensure steady stakeholder communication, and implement surveillance and outreach activities.

Contaminated Floodwaters

Floodwaters left over after hurricanes can contain a variety of hazards. CDC recommends that all individuals avoid floodwater. Potential hazards include sewage and other waste, debris from damaged structures, and damaged power lines. These hazards can pose infection, physical injury, and electrocution risks. Avoiding floodwater and practicing "good personal hygiene" (e.g., washing hands with clean water) can mitigate these risks. Flooding can also cause issues with septic systems, leading to sewage backups and other problems. If the system is damaged or malfunctioning, the Virginia Department of Health (VDH) recommends limiting the use of water and avoiding contact with sewage.


Mosquito Control

Although mosquitoes typically do not survive the powerful winds produced by a hurricane, conditions during or after a hurricane (e.g., flooding, standing water) can lead to an uptick in mosquito numbers. According to SCDHEC, “flooding causes ‘floodwater mosquito’ eggs, which were previously laid in soil, to hatch.” Floodwater mosquitoes generally do not transmit viruses, but their “biting pressure” can overwhelm residents and recovery workers. The American Mosquito Control Association (AMCA)’s Mosquito Management During a Public Health Emergency guide reports that populations of mosquito species able to transmit arboviruses (e.g., West Nile virus, Eastern equine encephalitis virus, Zika virus) can increase about "four or more weeks" following a hurricane, "but cases often occur infrequently immediately after a storm." SCDHEC recommends individuals cover exposed skin and use EPA-registered insect repellents to guard against mosquitoes. The AMCA guide linked above provides recommendations for mosquito control operations, as well as tips for community engagement.


Drinking Water and Food Safety

Drinking water and food safety are critical following a hurricane. Losing power can make it difficult to keep food properly refrigerated or frozen. Flooding can also lead to tainted drinking water supplies, including private wells, and expose food to harmful contaminants. Bottled water should be utilized for "drinking, cooking, and brushing teeth" in place of potentially contaminated tap water. Local authorities will have up to date information and guidance regarding the safety of local water supplies. Alternatively, boiling, disinfecting, or filtering can produce safe drinking water, although these methods won’t remove chemical contaminants or toxins. As outlined in the graphic linked above, CDC recommends boiling water, as it "will kill bacteria, viruses, and parasites." CDC also advises disposing of perishable food that may not have remained suitably refrigerated or frozen, food potentially contaminated with floodwater, and food having an “unusual odor, color, or texture.”


North Carolina Department of Health and Human Services

Food safety and sanitation issues in regulated food establishments and emergency shelters are the primary challenges the NCDHHS face following a hurricane. NCDHHS also encounters issues associated with flooding, such as indoor mold, private well sampling/testing, and mosquito control. Actions that NCDHHS takes to address these issues include:

Create and provide training programs for agency staff and managers/staff of regulated establishments

NCDHHS developed training modules for local health department staff on conducting shelter assessments. NCDHHS recommends providing training programs to managers/staff of food establishments on recommendations for reopening establishments and minimizing food safety risks after emergencies resulting in flooding or loss of power.

Develop emergency preparedness and response protocols ahead of hurricane season

NCDHHS recommends working on and finalizing emergency preparedness procedures during “off seasons” when these types of emergencies are less likely (e.g., developing hurricane protocols in the winter).


While it is important to call attention to the environmental health threats introduced during and after hurricanes, these issues represent a small slice of the toll these natural disasters take on communities, first responders, and agency staff. Before, during, and after the storm, agencies should consider mental health burdens, as stress and anxiety are common reactions to hurricanes and other natural disasters. CDC’s Response Resources for Leaders includes information on working with communities affected by disasters. Moving forward, ASTHO will continue to support its members and their staff in preparing for and responding to threats in communities hit by hurricanes and other natural disasters.

Special thanks to the North Carolina Department of Health and Human Services, South Carolina Department of Health and Environmental Control, and Texas Department of State Health Services for providing input used in this blog. Additionally, a special thanks to ASTHO’s Emma Talkington, Courtney Youngbar, Ericka McGowan, Alyssa Boyea, Sidnie Christian, and Amelia Poulin-Obregon for their support in developing this post.

Related Content

For additional information on considerations for state health agency hurricane response, visit Preparing for and Responding to Infectious Disease Threats Following Hurricanes: Considerations for State and Territorial Health Agencies.