Public Health Threats Emerging in Houston in the Aftermath of Hurricane Harvey

Julie SmythAlthough Hurricane Harvey's floodwaters have largely receded, public health threats are emerging over polluted floodwater and contaminated drinking water. Chemical pollution from damaged industrial sites, flooded toxic waste site, and contamination by infection-causing bacteria have been the main causes of concern. The U.S. Environmental Protection Agency (EPA) warned residents and cleanup workers who might be exposed to floodwaters to take precautions due to hazards such as dangerous debris, bacteria, and other contaminants. This article will review some of those public health threats.

Contaminated water

As a result of contaminated water systems, boil water notices have been issued for a number of systems in the Houston area. Texas Commission on Environmental Quality (TCEQ) reported that of about 2,238 drinking water systems affected by Hurricane Harvey, 2,014 systems are fully operational, 77 have current boil-water notices, and 19 are shut down. Of 1,219 wastewater treatment plants contacted by TCEQ in the 58 counties within the Governor's Disaster Declaration 31 are inoperable. One recent dataset released by TCEQ reported five destroyed and many inoperable community water systems across eight Texas counties and estimated that some systems will take weeks or months to repair.

The Texas Institute for Applied Environmental Research (TIAER) at Tarleton State University in Stephenville has pledged to monitor water and habitat quality by measuring hydrocarbon and bacterial contamination levels in flooded south Texas communities, according to TIAER's executive director Dr. Quenton Dokken.

"As floodwaters wash down streets, through garages and kitchens, across thousands of acres of farmland and through industrial areas, an A-to-Z list of toxic chemicals is flushed into the environment," Dokken said in a press release. "In addition, tons of manure and raw sewage are incorporated into this rancid brew."

Houston-area doctors have reported an uptick in soggy skin wounds and infections contracted by civilians and professionals exposed to floodwaters. The infections typically occurred when uncovered scratches or cuts were exposed to Harvey's floodwaters for long periods of time.

"Harvey changed the composition of our Labor Day weekend census from the typical overload of trauma cases from traffic accidents to a lot of soft-tissues infections," Dr. James McCarthy, chief of emergency medicine at Memorial Hermann Hospital's Red Duke Trauma Institute in Houston, told the Houston Chronicle.

Although most of the post-Harvey skin infections have responded well to antibiotics, McCarthy and Dr. Beau Briese, an emergency department doctor at Houston Methodist Hospital, told the Chronicle that they have seen a few severe infections, including ones that developed into life-threatening sepsis cases, which the doctors noted as unusual.

Toxic waste and chemical pollution

The EPA has 263 people deployed in response to Hurricane Harvey and is currently focusing water quality sampling efforts in south Texas on industrial facilities and hazardous waste sites, both of which have been points of concerns for Houston residents. As some Houston residents complained of strong chemical smells over parts of the city, ExxonMobil reported to TCEQ that two of its oil refineries near Houston were damaged in the storm, releasing harmful pollutants into the air. A floating roof at the company's Baytown refinery partially sank during Harvey's unprecedented rains, resulting in emission of the contaminants benzene, toluene, VOC (unspeciated), and xylene into the air.

Houston's Harris County hosts more federal Superfund toxic waste sites than any county in Texas and is home to a number of other toxic waste sites managed by the TCEQ. At least 14 Superfund toxic waste sites in the Houston area were reported as flooded during Hurricane Harvey. A number of toxins harmful to human health and environment have been housed at Superfund sites, including lead, arsenic, benzene, dioxins, asbestos, radiation, and other chemical compounds. Many have expressed concern that the floodwaters could spread these toxins into neighborhoods near the sites and affect residents' health through direct exposure to contaminated water, toxic water seeping into Houston's sewage system or private wells, or future consumption of seafood that absorbed the pollutants.

The EPA completed site assessments of all 43 Superfund sites in Texas and Louisiana affected by Harvey. Two sites, the San Jacinto Waste Pits and U.S. Oil Recovery, require "additional assessment efforts" as of the last update. The testing of samples taken from all Texas Superfund sites are expected to be completed this week and the results released soon.

EPA Administrator Scott Pruitt visited Houston on Friday to review the Agency's response efforts. In a statement given after his visit, Pruitt promised that the EPA would work closely with federal, state, and local partners to ensure Superfund sites would be properly secured and infrastructure and environmental assessments would be thoroughly carried out.

TCEQ completed assessments of all 17 state Superfund sites in the area affected by the storm and noted no major issues. TCEQ will continue monitoring the sites for storm-related issues.

Following the concerns expressed over Superfund sites flooded by Harvey, the EPA announced it was taking steps to secure the 22 current and former National Priorities List (NPL) Superfund sites in the path of Hurricane Irma prior to the storm's landfall. The EPA also deployed officers to Florida on Tuesday to assist in wastewater and drinking systems recovery in areas affected by Irma. The EPA stated that their Region 4 SESD Mobile Laboratory would be standing by to help USACE with sampling and analysis of drinking water for E. coli, fecal coliform, total coliform, and enterococcus in south Florida. The EPA has not released any information about the bacterial or chemical content of Irma's floodwaters at this time.

An open source mapping platform called Mapbox released a disaster map of the Houston area. The map gives Houston-area residents and official up-to-date information on areas with the highest risk of hazardous materials in flood waters.

Mold Infestations

Hurricane floodwaters bring with them another toxic public health hazard: mold. Floodwaters create conditions of what the World Health Organization calls “persistent dampness”, an environment ideal for the indoor growth of mold. Mold grows on organic materials, which it digests over time. These varicolored fungi will eventually destroy the material it grows on and then spread to adjacent materials, which it will also destroy. Mold reproduces by releasing spores into the air, which then land on other surfaces where they can grow. Mold's presence in the air and its ability to destroy organic materials make it a hazard both to people's homes and to their bodies.

Because mold colonies can begin growing on damp surfaces within 24 to 48 hours of water exposure, the U.S. Centers for Disease Control and Prevention (CDC) recommends drying up flooded building within 24 to 48 hours of flooding if possible and removing all porous materials, including drywall and carpeting, that have been wet for more than 48 hours. Even partially flooded homes and buildings are at risk of mold infestations in the walls. According to the National Capital Poison Center, break-down products of bacteria and molds as well as airborne chemicals, gasses, and particulate matter caused by the mold's destruction of materials can also be found in damp indoor environments. The havoc mold reeks on common building materials can also cause structural damage to flooded buildings.

Mold is more dangerous than you might think. According to an EPA fact sheet on flood cleanup revised in November 2012 after Hurricane Sandy, "During a flood cleanup, the indoor air quality in your home or office may appear to be the least of your problems. However, failure to remove contaminated materials and to reduce moisture and humidity can present serious long-term health risks. Standing water and wet materials are a breeding ground for microorganisms, such as viruses, bacteria, and mold. They can cause disease, trigger allergic reactions, and continue to damage materials long after the flood."

Indoor mold exposure is linked with upper respiratory tracts symptoms, coughing, and wheezing in otherwise healthy children and adults. People can have a variety of reactions to mold ranging from mild sensitivities to severe allergies and can even develop mold infection in the lungs. Some molds produce toxins or poisonous toxins called mycotoxins that are believed to affect human health. A small group of molds known as dimorphic fungi are pathogens capable of causing infections in healthy people as well as in people suffering from immune suppression.

People with immune systems weakened by medical conditions such HIV/AIDS or from the effects of certain prescriptions drugs or medical treatments such as chemotherapy are at a higher risk of developing lung infections. Severe reactions can occur among workers exposed to large amounts of mold, such as those involved in post-Harvey cleanup projects. Unlike the more immediate public health concerns following disasters, such as infections and mosquito-borne illnesses, mold exposure can continue to threaten human health for years after the disaster if proper steps aren't taken to remove contaminated materials from affected buildings.

Bacterial contaminants

Hurricane floodwaters from Harvey and Irma are both known to contain sewage from flooded plumbing and waste systems, encouraging the spread of harmful bacteria. A test conducted at Texas A&M University of floodwaters samples from the Houston area showed E. coli levels that were 125 times higher than is considered safe for swimming. Dr. Terry Gentry, an associate professor in Texas A&M's Department of Soil and Crop Sciences concluded that even walking through floodwater as the tested water proved to contain E. coli 15 times higher than the acceptable levels for wading.

"We saw elevated levels of E. coli," Dr. Gentry told ABC's Good Morning America. "And this indicates the very likely presence of pathogenic bacteria, viruses and other types of organisms that could cause disease in some individuals."

The New York Times also organized a test of floodwaters in several Houston neighborhoods and found alarming levels of Escherichia coli present around and inside houses. Floodwaters running down Briarhills Parkwy in the Houston Energy Corridor contained a level of E. coli four times higher than what is considered safe. One living room in the Clayton Homes public housing development in downtown Houston contained levels of E. coli 135 times higher than those considered to be safe.

Residents in areas affected by Harvey and Irma whose homes operate on well water systems rather than on public sanitation are being encouraged to have their wells tested for E. coli and total coliforms. Flooded wells have a high likelihood of contamination by harmful microbes and chemicals washed in by the storm.

A CDC alert warned those affected by Hurricane Harvey about the risk of developing Vibrio infections for those in areas affected by recent hurricanes and coastal flooding. The CDC estimates 80,000 Vibrio infections occur in the United States every year, the majority of which are caused by eating contaminated seafood. However, "certain Vibrio species, including Vibrio vulnificus, can... cause a skin infection when an open wound is exposed to brackish or salt water," a fact sheet linked to the CDC alert said. "When a hurricane or storm surge causes flooding, you may be exposed to coastal water."

Vibrio vulnificus, Vibrio parahaemolyticus, and Vibrio alginolyticus are the three most common Vibrio species native to the U.S. Gulf Coast waters. Most mild cases of vibriosis (an illness caused by Vibrio bacteria allow for a quick recovery with no lasting effects, but infections caused by Vibrio vulnificus can cause patients to become seriously ill or require limb amputation as this infection eats the flesh around the affected area. According to the CDC, one out of every four patients with a Vibrio vulnificus infection dies, sometimes within a day or two of infection. The southern U.S. experiences an uptick in Vibrio infections in the months after Hurricane Katrina, including five deadly cases. Vibrio cases are expected to rise after natural disasters such as hurricanes, so Vibrio infections are an ongoing public health hazard for southern Texas and south Florida.

Vibrio species are usually susceptible to antibiotics, but studies are reporting that two species common in the United States, Vibrio vulnificus and Vibrio parahaemolyticus, have been developing resistance to multiple antibiotics as a result of misuse of antibiotics in the seafood industry. Some strains of E. coli have also demonstrated resistance to multiple-antibiotics, including some strains that are resistant to the carbapenem class of antibiotics or the last-resort antibiotic colistin. So far, no antibiotic-resistant infections have been reported in the aftermath of either Harvey or Irma.

Mosquito-borne Illnesses

Although Hurricane Harvey's high winds likely killed most of the adult mosquito population during the storm and massive flooding likely washed away mosquito breeding sites, experts are concerned that standing water left behind by the floods creates a perfect breeding habitat for mosquitos to reestablish their populations.

Mosquitoes can lay a whole lot of eggs in a small patch of standing water. Mustapha Debboun, director of mosquito control for Harris County told CBS News that two car tires filled with water could allow mosquitoes to breed between 500-700 mosquitoes. Flooded swimming pools that have been left untreated are a perfect habitat for mosquito breeding.

According to the CDC, mosquito eggs laid in the soil by floodwater mosquitoes during previous flood will hatch in the post-hurricane floodwaters, resulting in a large population of floodwater mosquitoes, most of which are considered “nuisance mosquitoes” that do not generally spread viruses that cause illness in people. However, large numbers of nuisance mosquitoes can affect recovery efforts and people spending more time outside during cleanup efforts are more likely receive nuisance mosquito bites. Lara Hamilton, the executive director at Christ Clinic in Katy, TX, told NBC news that "We are seeing people who have just been eaten up by mosquito bites. Typically, people won't go to the doctor for mosquito bites."

In areas that did not flood but received more rainfall than usual, virus-spreading mosquito populations may increase two week to two months after a hurricane. Duane Gubler, an emeritus professor in the Emerging Infectious Diseases Programme at Duke-NUS Medical School told Vox that any increase in transmission of mosquito-borne diseases will likely be from West Nile and Eastern equine encephalitis, both of which are always present in United States bird and mosquito populations.

In response to the problems presented by nuisance mosquitoes making it difficult for recovery workers to stay outside and the possible reemergence of disease-spreading mosquitoes, the Texas Department of State Health Services (DSHS) began aerial mosquito control efforts on September 7 with flights over several counties affected by storm to apply aerial insecticides. Clarke, Texas' environmental service contractor, is using three twin-engine Beechcraft King Air planes to disperse the insecticide. The U.S. Air Force Reserve is assisting in the effort, using modified C-130 cargo planes from Kelly Air Force Base in San Antonio to spray about 600,000 acres in the northern and southern thirds of Harris County.

Mental and Behavioral Health

In addition to the economic losses and physical health hazards resulting from hurricane damage, storms like Hurricane Harvey can take a toll on the mental health of those affected by the storms. According to the Substance Abuse and Mental Health Services Administration (SAMHSA), emotional distress is a normal experience for flood survivors. Residents of a disaster area often experience anxiety over their anticipated losses before and during the flood.

Overwhelming anxiety, feelings of hopelessness or helplessness, constant conflicts with friends and family, constantly recurring disaster-related thoughts or memories, or loss of sleep are some signs of emotional distress that can affect flood survivors, first responders and recovery workers, and even the friends and family of those impacted by the disaster. Some may have difficulty coping with traumatic events witnessed during the storms. Children are particularly vulnerable to storm-related trauma because of the loss of their normal routine and sense of safety.

Studies done after Hurricanes Katrina and Sandy indicated that up to 50 percent of those who survived being in the storm's direct path and 10 percent of those living in the vicinity of the storm are at risk of developing symptoms of post-traumatic stress disorder (PTSD). Some academic literature also suggests that 10-20 percent of rescue workers may also develop symptoms of PTSD. Rates of major depressive disorder (MDD) and substance abuse may also rise after disaster like Harvey, which women being more affected by MDD and men being more affected by substance abuse problems, such as consuming alcohol or some drugs to cope with stress.

The emotional and mental impact of Harvey on south Texas residents is likely to continue in the months to come. Returning to sites impacted by flooding, anniversaries of the event, and some environmental sensations may trigger emotional distress even after the event is over, according to SAMSHA. Additional stress can occur when families and individuals are temporarily or permanently relocated after the hurricane and as residents who return to their home begin the long process of attempting to rebuild their lives.

Another issue is the impact Hurricane Harvey likely had on residents already being treated for mental health conditions. Some residents were unable to take their medicines with them when they evacuated, were rescued, or moved into shelters. This disruption in care and medication can have a range of consequences for mental and behavioral health. Access to care for both those with preexisting mental health conditions and those with hurricane-related mental health issues may be limited as hospitals and mental health providers also recover from storm-related damage.

Mental health needs tend to be overlooked amid myriad other health threats introduced by hurricanes, but a number of mental health professionals are trying to ensure that the people of Houston get the help they need. The Houston Independent School Districti has worked with social workers, counsellors, and nurses to develop a “mental health recovery plan” for helping traumatized students coming back to school in the district's hardest hit schools. Walgreens, CVS, and Walmart all made donations to help those with mental health diagnosis get the medications they needed after the storm. Mental Health America of Greater Houston set up two children's zones for evacuees sheltered at the George R. Brown Convention Center. Both MHA of Greater Houston and the American Red Cross called on mental health professionals to volunteer to help Harvey survivors.

“Having experienced many hurricanes and having provided emergency mental health care to hurricane survivors, I have witnessed the complexities associated with recovery from devastating storms,” American Psychological Association President Antonio E. Puente said in a statement. “There is no easy or quick solution to the destruction and subsequent loss associated with something as catastrophic as Harvey. Healing - both physically and mentally - will take a long time.”

As the U.S. coastline continues to be threatened and hit by other hurricanes such as hurricanes Irma, Jose, and Maria, it will be vital to ensure that Houston residents continue to get the mental and physical health care they need even as other storms take the national spotlight.

The future of disaster response

Hurricanes will continue to menace the U.S. coast, threatening residents with toxic and chemical waste spills, the possibility of antibiotic resistant disease outbreaks, mental health difficulties, and mosquito-borne illnesses. Policy makers and public health experts must identify the problems, seize the opportunity to learn from Harvey and Irma, and collaborate to create solutions for responding to disasters and preventing unnecessary threats to human health. If they don't, the fallout from future hurricanes could be much, much worse.

But it is ultimately up to individuals and local responders, towns, cities, municipalities to be prepared and to build resiliency into their plans. This is a message that FEMA’s new director, Brock Long, has been making. In an interview with several journalists on September 11, he said:

“I really think that we have a long way to go to create a true culture of preparedness within our citizenry in America. No American, no citizen, no visitor to this country is immune to disaster. And we have a long way to go to get people to understand the hazards based on where they dwell, where they work, and how to be prepared financially, how to be prepared through insurance, how to have continuity of operations plans for their businesses, so that we can avoid the suffering, the strife, and the loss of life. It’s truly disappointing that people won’t heed the warnings.”

The American people need to heed this call.