Public Health and Flood Waters:
Tips for dealing with Health, Safety and Environmental Issues

Introduction

During and following a widespread flooding disaster, many questions arise from citizens within the communities affected, and from the many volunteers and organizations which are working in the devastated area. Personal health and safety is a priority for everyone. The following information is aimed at preventing both disease and injury.

Local, state and federal agencies work closely together to provide multi-faceted services and to also provide information which will enable citizens to maintain optimum health during an extended period of clean-up and recovery.

Many misconceptions occur during such natural disasters and cause valuable time to be diverted from critical public health activities. This document is an attempt to answer many common concerns and provide valuable preventive health tips.

What immunizations will I need if I am exposed to flood water?

No special immunizations are necessary. Experience and studies from previous serious national floods demonstrate that increased risk or incidence of tetanus, typhoid fever or hepatitis A have not occurred. Recommendations for these immunizations are the same as during non-flood conditions. These recommendations are based upon the recommendations of the Council of State and Territorial Epidemiologists.

• Tetanus - A booster for tetanus should be given to anyone sustaining an injury (particularly lacerations and puncture wounds) that has not received a vaccination within the last 10 years, 5 years for particularly major or unclean wounds.
• Hepatitis A - Immune globulin is given only to those persons known to be in direct contact with a confirmed case of hepatitis A. Hepatitis A vaccines are not required.
• Typhoid - Prophylactic Typhoid vaccination is not recommended.

What disease-causing agents may be present in floodwaters?

Since county and city water systems may become contaminated and power outages are widespread following severe flooding, increased foodborne and waterborne diarrheal illnesses may occur among the population. A variety of sources, including animal and human waste, can contribute to water pollution. It is important for physicians to test for and identify agents of illnesses so that outbreaks may be prevented and controlled in a timely and effective manner. Reporting of these diseases by physicians and laboratories to local health departments is necessary so cases can be investigated to determine if there is a common source.

• Diarrheal Illness - Most diarrheal illnesses have incubation periods between one and seven days. Bloody diarrhea may occur with certain infections. Testing for illness should be performed prior to treatment with medication because of the large number of causative agents that may require different antibiotics. Stool cultures submitted by your physician can be tested at the State Laboratory for Public Health. Local health departments should be notified of the results so cases can be investigated and appropriate follow up provided.
• Hepatitis A - If hepatitis A is suspected, the doctor should draw blood and test for IgM antibodies for hepatitis A. It is especially important for the local health department to know if a person with this illness is a food handler or participates in a day care setting.
• Parasites - Some waterborne parasites (e.g., giardia, cyclospora, and cryptosporidium) may also cause chronic diarrhea; testing by a physician can identify these diseases. Such diseases can be severe in immunocompromised persons.
• Leptospirosis - During widespread flooding of an area there may be a potential, but small, risk for a disease called leptospirosis, which is caused by exposure to animal urine. It is a bacterial disease that affects both humans and animals. Symptoms may range from none to high fever, headache, chills, muscle aches, vomiting, jaundice (yellow eyes and skin), abdominal pain, diarrhea or rash. If the disease is not treated, kidney damage or liver failure may develop as well as respiratory failure or meningitis. Death occurs rarely.

  Leptospirosis may be confused with other diseases and must be confirmed by laboratory testing, available through the State Laboratory for Public Health. Although most livestock are vaccinated against this disease, they may still excrete bacteria; however, urine from dogs, rodents, and other wild animals may also be infected. Humans can be infected through contact with water, food or soil containing animal urine or tissue. Swallowing floodwater or exposure to mucosal surfaces such as eyes, nose or skin may also produce illness. Person-to-person spread is rare. If infected, a person can become sick between 2 days and 4 weeks. The illness may occur in two phases: the first with symptoms described above followed by a short recovery; if a second phase develops, it is more severe. Treatment is important to prevent more serious illness and a more lengthy recovery. Risk for this disease will be greatly reduced by not swimming or wading in floodwaters. It is also helpful to wear protective clothing or footwear and gloves when possible. All incidence of disease should be reported to the local health department for follow-up.

What is the health risk when caskets are unearthed by floodwaters?

While this is a sensitive issue, unearthed caskets and embalmed bodies do not pose a public health risk. Caskets should be retrieved and secured until they can be identified. Unearthed caskets must be properly reburied. Any members of the public who find a body should report it immediately to local law enforcement authorities. Persons handling bodies should wear gloves.

What problems can I encounter with flooded buildings?

Residents working on or living in buildings damaged by water during flooding should be aware of the potential for biological contamination to their homes and drinking water. If homes become flooded or wells are covered with water as a result of the flood, then certain measures should be taken in order to protect your health and safety. The following describes the public health problems associated with flooding, the misconceptions associated with flooding, and the measures to take to protect your health and safety after a flood.

• Mildew, Mold and Fungi - Mold (fungi) will grow in flooded buildings that do not dry out quickly. People living or working in buildings with wet carpet, walls, mattresses and/or furniture can have health problems such as allergies, asthma, (a form of troubled breathing), and sneezing. Mold and fungi can grow in these materials to numbers that can present a health risk after being wet for only 48 hours. Persons at highest risk are asthmatics, people with allergies, infants and children, elderly, pregnant women, people with existing respiratory diseases, and people with compromised immune systems. Spraying with a household disinfectant for fungi and mold will not remove the organisms and can exacerbate breathing problems.

  TIP: Porous or spongy materials including carpet that have been saturated with floodwaters should be thrown away. Scrub hard surfaces of your home and its dried contents with warm soapy water using laundry detergent. Rinse with clear water, and rinse again with a biocidal solution (1/4 cup of household bleach to 1 gallon of water). Allow the biocidal solution to stay in contact with the surfaces for five minutes and rinse again with clear water. Avoid skin contact with the biocidal solution and use only in well-ventilated areas. Wash all clothing items in hot soapy water. Contaminated mattresses, upholstered furniture and carpets should be discarded because they cannot be thoroughly cleaned and dried. All cleaned items should be thoroughly dried, or mold and mildew will return.
  
  TIP: Personal protective equipment should be worn when entering a flooded building. It is recommended to wear boots, puncture resistant gloves, and respiratory protection against mildew, mold, and fungi that may be in the air. The type of respirator that is recommended is known as a filter face piece respirator that can be obtained at a local hardware store. Look on the label for NIOSH N-95 filtering face piece with N-95 organic vapor for odor control.

• Contaminated Drinking Water - Unhealthy bacteria may be present in residents' water if the public water supply has lost power or if a private well has been flooded. The water in the home may be unsafe for drinking, cooking, or washing. Many water lines run parallel to roads. If floodwater recedes too quickly, it can erode the ground under the roads, causing the roads to collapse and in turn break the water lines. This may contaminate public drinking water supplies and disrupt service.

  TIP: If residents' public water supply has lost power or if a resident's private well has been flooded, the water for drinking, cooking, making ice, brushing teeth, and bathing should be boiled for approximately 3 to 5 minutes. Because boiling water can increase nitrate levels seen after flooding, young infants and pregnant women should not drink boiled water. Bottled water should be used by pregnant women and be used for preparing infant formula. If you cannot boil the water, add plain household bleach (which is 4% to 6% chlorine) using 1/4 teaspoon per gallon, shake, and let stand for 30 minutes. Water should have a slight bleach odor. Residents should continue with these procedures until tests show no bacteria in water. Customers of public water systems do not need to test their water. The operator of the public water system will conduct these tests. Private well users should contact their county health department for information on testing well water.
  
  TIP: People do not need to have their water tested if they are on a public water supply. The operator will conduct proper testing once floodwaters recede and power is restored. The state or local health departments will not take samples from homes served by a public water supply.

• Asbestos Building Materials - Homes may have building materials containing asbestos, which has been associated with respiratory diseases. Building materials that may contain asbestos include flooring, siding, roofing, pipe insulation, fireproofing, or decorative ceiling treatments.

  TIP: If asbestos is suspected to be present in building materials, the materials should be carefully wetted to minimize dust production whenever they are being disturbed or moved from place to place. To obtain information, contact the Division of Public Health, Health Hazards Control Unit at 919-733-0820.

• Sewage - Flooding may cause wastewater to back up into homes that receive wastewater service from either private or community septic systems. Once the water recedes, a high water table may still prevent these systems from functioning for some time.

  TIP: Wear rubber boots and waterproof gloves during cleanup if sewage backed up into your home. Remove and discard contaminated household goods such as wall coverings, rugs, cloth and drywall that cannot be disinfected.

What concerns should I have about wild animals and insects?

• Mosquitoes - Flooding can result in excessive breeding of mosquitoes, resulting in the possibility of diseases being carried by the insects. Swarms of mosquitoes may be seen in the affected regions for several weeks after the storm. Mosquito eggs can lie dormant for years without water. Those eggs will now hatch increasing the potential for mosquito-borne disease until the first frost. State and local pest management officials will address this problem.
  TIP: Residents should remove water from birdbaths, flower pots, tires, buckets and other containers to minimize the breeding of mosquitoes. Use of repellants containing DEET is highly recommended to prevent mosquito bites. It may be necessary to have aerial spraying for mosquitoes. Please contact your local county health department for aerial spraying schedules. Although there is minimal risk to residents, it is advisable to stay indoors during aerial spraying.
• Other Insects - Bees, wasps, and hornets may have had their nests disturbed by excessive wind and rain. These insects can become very aggressive.

  TIP: Before beginning cleanup, survey the site to see if bees, wasps or hornets are hovering in the area. If they are, use a commercially available pesticide labeled for control of these insects to get rid of them before entering.

• Snakes - Snakes will also have their habitats disturbed during flooding. Also, there is less land for them to seek shelter and they are prone to enter abandoned homes, vehicles, furniture and equipment.

  TIP: Before reentering homes or vehicles, and before placing furniture back in the home, check thoroughly for snakes.

• Wild Animals - Wild animals displaced from their natural habitats may seek shelter in places where they may be exposed to people. Such animals may be infected with rabies.

  TIP: You should avoid contact with wild animals such as raccoons, possums, squirrels, etc. Animal bites should be reported to the local health department or the N.C. Veterinary Public Health Program at 919-715-6421.
  

• Dead Animals - Dead animals may be found around your home after a flood. The presence of these animals may result in excessive odor and increase in the number of flies. Widespread contamination from animal waste and untreated sewage may occur. The presence of carcasses can serve as reservoirs for those known organisms, such as coliforms, and will attract vectors such as flies that can contaminate food. "Hog cholera," which is caused by a virus and is not transmissible to humans, has not been seen in the state for several years. Hog cholera and human cholera are not the same disease.

  TIP: Small dead animals found around the home may be placed in dumpsters or buried three feet in the ground. Do not handle with bare hands. If large livestock are found, it is recommended to notify a local cooperative extension agent to determine the appropriate disposal method.
  

General Health Tips

• The important considerations and recommendations for the public in flooded areas are avoidance of sewage, debris, and remains of animals. When handling is necessary for disposal, use protective equipment such as gloves to avoid direct contact. Always use good handwashing practices during this time. It is especially important to wash your hands with soap before smoking, eating or drinking.

For More Information

The following phone contacts may be of value in answering particular questions that may arise:

• State Emergency Hotline 1-888-835-9966
• To apply for federal disaster assistance (FEMA) call 1-800-462-9029.
• For concerns about disease outbreak call the General Communicable Disease Control Branch at 919-733-3419.
• Questions regarding asbestos and worker protection, indoor air quality, livestock control and carcass removal, sewage backwash, mildew and mold, well contamination, and chemical toxicity will be answered by consultants in Occupational and Environmental Epidemiology at 919-733-3410 or your local water system.
• For environmental health concerns such as water quality, waste water and public water issues call 919-733-7015.
• Pest Management Control will answer questions about insects at 919-715-3287.
  

For more information on cleaning up after a flood, contact your local Emergency Management Office, county health department or Red Cross chapter. You can also get information from the following internet sites:

• Red Cross
• Federal Emergency Management Agency: FEMA
• NC Department of Health and Human Services

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