Toxic Floodwaters on the Gulf Coast and Beyond: Commentary on the Public Health Implications of Chemical Releases Triggered by Extreme Weather

CLIMATE CHANGE AND SHORTSIGHTED LAND USE DECISIONS HAVE LEFT COASTAL COMMUNITIES VULNERABLE TO HARM FROM FLOODS

As the effects of climate change amplify, changing patterns in hurricanes, precipitation, and sea level rise will increase both the intensity and frequency of storm surges and coastal flooding in the United States. ¹ According to the National Oceanic and Atmospheric Administration, the regions most vulnerable to flooding and sea level rise are the Gulf Coast, Eastern Seaboard (especially Southeastern states), and the Pacific Northwest. ² The social and economic implications of these projections are significant. More than half of the U.S. population (164 million people) lives or works in coastal counties, generating 58% of the nation's gross domestic product. ³

The extent of the likely damage from extreme weather-related flooding is difficult to control and related to various factors, such as the presence of flood-resilient infrastructure, population density, and public awareness about flood risks. ⁴ While some cities and towns are taking action to protect against flood hazards, a 2015 assessment of local land use plans found that many do not adequately protect areas most vulnerable to flooding, and in some cases, the plans increase physical and social vulnerability to hazards. ⁵ Such lack of preparedness was a major factor in the devastating damage from Hurricanes Katrina and Harvey in New Orleans, Louisiana, and Houston, Texas, demonstrating just how ill-prepared states and cities are for the effects of climate change.

Mindful of events such as Hurricane Harvey, experts are increasingly concerned about chemical releases triggered by extreme weather. Thirty-nine percent of the U.S. population (124 million people) live within 3 miles of a high-risk chemical facility. ⁶ Many of these facilities are in low-lying coastal areas; for example, the hurricane-prone Gulf Coast has 872 highly hazardous facilities within 50 miles of the coast. ⁷ More than 4.3 million people live within 1.5 miles of these facilities. ⁸

Focusing on one region, in 2019, a Center for Progressive Reform assessment found that 1000 industrial facilities housing hazardous chemicals in Virginia's James River watershed are in the area's most socially vulnerable communities and are at risk of flooding from storm surges or sea level rise. ⁹ Nearly half a million Virginians live in these communities.

As the effects of climate change intensify, data show that these releases are happening more frequently. A 2012 analysis of reports made to the National Response Center, which tracks oil, chemical, radiological, biological, and etiological discharges, found that hazardous material releases due to natural hazards increased in frequency between 1990 and 2008. ¹⁰ Hurricane-related releases increased 15-fold from 2005 to 2008, and weather- and storm-related releases rose by 8% and 5% during the study period, respectively.

CHEMICAL RELEASES DURING EXTREME WEATHER EVENTS HARM NEARBY COMMUNITIES, PARTICULARLY HISTORICALLY DISENFRANCHISED POPULATIONS

Plant workers and residents who live near hazardous facilities may be exposed to chemicals through chronic leakage into air, water, and soil, or through major releases when facilities are compromised. During a severe storm, storage tanks or pipes containing chemicals, for example, may be dislodged, damaged, or ruptured, and their contents washed into floodwaters. ¹¹ Lightning can also ignite flammable materials, causing fires or explosions, and rising waters can damage the power supply and control processes that contain stored materials. A 2019 assessment of the U.S. Chemical Safety Board's incident screening database, which tracks fires, explosions, and chemical releases at industrial facilities, found 9406 reported incidents between 2001 and 2018 (average of roughly 1.5 incidents per day). ¹² Approximately 40% of incidents in the database led to injury or death among workers and/or the public. One extreme weather event can also have long-lasting and far-reaching impacts. For example, between 2005 and 2008, more than 1070 hazardous material releases in Louisiana, Mississippi, Alabama, and Florida were attributed to Hurricane Katrina alone. ¹³ These releases were largely the result of storage tank failures, which tend to yield the largest releases by volume. ¹⁴

The public health impacts of extreme weather-related chemical releases are difficult to predict with accuracy because communities are exposed to different mixtures of chemicals that, when released and combined with whatever else is present in floodwaters, may produce a variety of effects. ¹⁵ A study of hurricane-related chemical releases from facilities in Louisiana and Texas in 2005 found that 197 different hazardous substances were released in 166 events. ¹⁶ In most cases, only one hazardous substance was released per event, but in some instances, as many as eight were released. Among the more common toxicants released are volatile organic compounds, polycyclic aromatic hydrocarbons (PAHs), petroleum, and heavy metals. ¹⁷ Floodwaters may also stir up existing contaminants present in soil and waterways, forming a “toxic soup.” ¹⁸

Exposure to flood-related chemical releases can contribute to many short-term ailments, such as dermatitis, rashes, burns, headaches, fatigue, abdominal pain, fever, decreased appetite, nausea, sore throat, and eye irritation. ¹⁹ These effects can compound existing hazards associated with flooding, such as drowning or injury from contact with debris, disruption of medical and emergency relief services, and displacement. ²⁰ Some contaminants, such as heavy metals, may also adsorb to sediments and redistribute throughout an area with floodwaters. ²¹ For example, elevated levels of lead and arsenic were found in soil samples in New Orleans and New York City following Hurricanes Katrina and Sandy. ²² This can be especially hazardous to children due to their increased likelihood of exposure and susceptibility to contaminants in soil. ²³ If mold or chemicals that accumulate in homes, workplaces, and schools are not adequately remediated, chronic exposure may contribute to occupants developing respiratory conditions, cancers, or other diseases long-term. The stress associated with flooding and displacement can also contribute to onset or exacerbation of mental health conditions such as post-traumatic stress disorder. ²⁴ For example, a survey completed nearly 6 months after Hurricane Katrina found that the prevalence of anxiety-mood disorders was nearly twice as high among New Orleans metropolitan area residents compared with people outside the region who were also exposed to Katrina. ²⁵

The public health burden of extreme weather-related chemical releases is disproportionately felt by historically disenfranchised communities. Due to a legacy of redlining, exclusionary zoning practices, and other systematic forms of housing segregation, the vast majority of people who live near chemical facilities are Black, Hispanic, and have low wealth. ²⁶ An analysis of federal flood insurance payments also found that flooding disproportionately harms primarily Black neighborhoods. ²⁷ Of the seven zip codes that experienced the costliest damage from flooding following Hurricane Katrina, four had populations that were at least three-quarters Black.

Poor families and Black and Hispanic communities may already grapple with a range of social stressors rooted in oppression, such as inadequate access to health care and healthy food options, substandard housing, and less access to generational wealth. ²⁸ These existing social stressors, compounded by the effects of flooding and toxic exposures, can lead to a greater cumulative burden felt by these communities, leaving them at a higher risk of “debilitating damage, uncompensated loss, and long-term suffering.” ²⁹ Children, the elderly, incarcerated people, and people with disabilities are also particularly vulnerable to harm from floods. ³⁰

Flooding during Hurricane Florence illustrates the disproportionate impacts of extreme weather on Black communities. When Florence hit North Carolina in 2018, inadequate safety measures led to releases of coal ash and caused hog waste “lagoons” to overflow into nearby communities. ³¹ Research shows that industrial hog facilities are disproportionately permitted near communities of color in North Carolina, and for years before the hurricane, health outcomes have been worse among residents living near hog-concentrated animal feeding operations. ³² Flooding and exposure to additional toxic contaminants only worsened the existing burden felt by these communities.

Finally, while the primary focus of this commentary is community-level effects, emergency response and clean-up workers are also at risk of harm from extreme weather-related chemical releases. Some hydrocarbons can damage neoprene protective wear, and wetsuits may increase skin contact with chemical contaminants. ³³ Furthermore, in a survey of New Orleans firefighters 3 months after Hurricane Katrina, 38% reported one or more respiratory symptoms and almost half—most of whom had contact with floodwaters—reported skin rashes. ³⁴ Workers performing post-disaster repairs or demolitions can also inhale dust containing chemical contaminants and heavy metals. Another study of New Orleans construction workers noted elevated cases of pneumonia, asthma, and transient fever and cough following Hurricane Katrina. ³⁵

HURRICANE HARVEY, A CAUTIONARY TALE FOR DISASTER

Hurricane Harvey is one of several recent disasters that demonstrate the public health harms of chemical releases triggered by extreme weather. In 2017, the Category 4 hurricane dumped up to 50 inches of rain on Houston, Texas, and surrounding areas. ³⁶ Forty-six industrial sites released ∼4.6 million pounds of hazardous materials from preemptive shutdowns and startups, leaks, or explosions, and several Superfund sites were underwater for days. ³⁷ Of particular note, flooding at the Arkema chemical plant in Crosby, Texas, disabled the refrigeration system, causing organic peroxides to explode. ³⁸ As a result, 21 people sought medical attention and hundreds within 1.5 miles of the plant evacuated their homes.

Despite presumed dilution of contaminants by floodwaters, heavy metal concentrations in stream water increased after the hurricane, demonstrating the sheer volume of contaminants present. ³⁹ Furthermore, an assessment of Manchester—a Houston neighborhood of around 4000 people with 21 toxic facilities within 1 mile—found that households were exposed to elevated levels of PAHs through dust and outdoor soil redistributed by floodwaters. ⁴⁰ Long-term exposure to PAHs contributes to an elevated risk of developing breast, lung, gastrointestinal, and bladder cancer. Most of Manchester's residents are Hispanic with a median household income one-third less than Houston overall.

After the storm passed, Manchester residents noticed a foul persistent odor. Sandra Martinez, who lived in the neighborhood with her husband and six children, said, “You could literally smell it in the house … I just pray for my kids. Because you don't know if there was a chemical spill.” ⁴¹ After 10 days of experiencing bronchitis, asthma, nausea, nosebleeds, headaches, and stomachaches, the family felt that they had no option but to move elsewhere.

In a survey completed 1 year after the hurricane, one in six Texas Gulf Coast residents said their quality of life was worse overall, and another one in six said that someone in their household had a new or worse health condition as a result of Harvey. ⁴² Nearly one-third of respondents also reported declines in their own mental health. Black and lower income residents were more likely to say that their lives were disrupted by the storm and were more likely to report financial hardships, further demonstrating the disproportionate impacts of extreme weather events.

GREATER TRANSPARENCY AND OVERSIGHT OF INDUSTRIAL FACILITIES WILL PROTECT THE MOST VULNERABLE COMMUNITIES FROM HARM

The effects of climate change are upon us, and recent extreme weather events provide ample evidence of the folly of leaving toxic chemicals in the path of predictable floodwaters. Since it is difficult to control the effects of extreme weather-related chemical releases, experts recommend a preventative approach to protect public health. ⁴³ Researchers also project these events to become more frequent, “whether due to more development in hazardous areas, anthropogenic climate change, or natural variation.” ⁴⁴

While awareness of these events has grown over the last decade, they are inadequately regulated at the federal, state, and local level. Currently, neither the U.S. Occupational Safety and Health Administration nor the Environmental Protection Agency require facilities to comprehensively address extreme weather and flood risks in required pollution prevention and management programs. ⁴⁵ In 2019, the Center for Progressive Reform completed a review of federal and state laws and programs that regulate hazardous chemical facilities. The report identified several opportunities that lawmakers and regulators can pursue to reduce risk of toxic floodwaters and protect communities from harm. ⁴⁶

The federal Emergency Planning and Community Right to Know Act (EPCRA) was enacted to provide the public with information about the hazards of polluting industries. EPCRA requires public disclosure of Tier II facility reporting data to alert communities when a facility is storing “extremely hazardous substances.” The law also requires annual reporting of toxic chemical releases; however, many states have not followed through on providing the public with access to this information under the guise of national security concerns. ⁴⁷ State regulators should immediately reverse policies that prevent public disclosure of this information. For example, Illinois' Emergency Management Agency has a publicly accessible and searchable database for Tier II facility reporting data.

Furthermore, there is currently no federal program regulating aboveground storage tanks, which are vulnerable to extreme weather events and flooding. State lawmakers and regulators should work together to establish a comprehensive regulatory regime for aboveground storage tanks. Such a program should require siting and construction standards for new tanks to prevent or limit damage from flooding, require leak monitoring devices and secondary containment mechanisms, and set maximum age limits for tanks and require regular inspections.

Finally, regulators in coastal or riverine states with a high concentration of high-risk chemical facilities should complete a statewide analysis of the climate vulnerability of industrial facilities and conduct a risk assessment of climate-related chemical disasters. The analysis should consider impacts to historically disenfranchised communities that may already be exposed to social and environmental stressors. Regulators in affected states should also limit permit eligibility based on climate vulnerability and require permitted facilities to implement climate-responsive spill prevention practices, among other reforms. Furthermore, regulators should prioritize inspection and enforcement in communities that have been identified as being vulnerable to flooding and social stressors.

To bolster these efforts, lawmakers in affected states should establish and fund a task force to investigate ways to improve pollution permitting and other strategies to prevent climate-driven chemical disaster. The task force should engage key stakeholders, including regulating agencies, affected communities, and industry.