Nature and Extent of Environmental Exposures
SHORT- AND LONG-TERM ENVIRONMENTAL HEALTH CONCERNS IN THE GULF COAST REGION
The role of the Centers for Disease Control and Prevention (CDC) in emergency response is part of the national response plan for disasters. The agency is involved in the preparedness and planning phases before and during the impact of any event, from predeployment through response and recovery. This response encompasses a wide range of activities, including the strategic national stockpiling of medications, preparedness grants (approximately $800 million) from CDC to the states, and a number of other activities involving the National Center for Environmental Health and the Agency for Toxic Substances and Disease Registry (NCEH/ATSDR). NCEH/ATSDR has lead responsibility during chemical, radiation, and natural disasters, and it played a major role in the response to Hurricane Katrina. The center deployed approximately 600 people in response to Hurricane Katrina and nearly 100 for Hurricane Rita. Personnel deployed by CDC were involved in a wide range of activities, including performing assessment surveys, serving as liaisons with federal and state agencies, contributing directly to rebuilding the public health infrastructure, and participating in vector and animal control. The agency generated many public-education materials, which were moved through the clearance process expeditiously. They were made available to people in the affected region and were posted in the Katrina section of the CDC website.
According to Howard Frumkin of NCEH/ATSDR, the agency produced a daily dashboard that was widely distributed by e-mail each day, listing real-time information on health activities and plans concerning the following issues:
The city emergency operations center,
The health care system,
Damp indoor spaces,
Occupational safety and health,
Human immunodeficiency virus, sexually transmitted diseases, and tuberculosis program evaluation, and
Environmental health issues, including water, sewer, solid waste, vector control, and food.
Social, Scientific, and Organizational Challenges
A range of agencies, including the Department of Health and Human Services (DHHS), the Federal Emergency Management Agency, the Department of Homeland Security, the Environmental Protection Agency, and the Department of Defense, are the first to respond to disasters when federal assistance is necessary. State and local agencies also have important responsibilities that sometimes, but not always, overlap with federal agencies’ responsibilities and can lead to a very complex set of challenges. The central challenges were communication among the agencies and responding to environmental health issues. Housing quality and levels of mold in private homes proved to be particularly difficult to address because these issues do not belong to any particular agency.
Throughout the course of the hurricane response, situational awareness and data management were a challenge. The agencies and organizations involved in the response amassed considerable data; however, there was a lack of centralization of these data in a data repository. Furthermore, sampling results could be easily found; however, interpreting the
In the absence of complete data, we need rapid interpretation of the data we do have, coordination among the various agencies in performing this interpretation, and consistent messaging to the public and policy makers.
meaning of the results for both policy makers and the public in order for them to make decisions was not easy. Inconsistent messages coming from multiple sources created difficulties for the widely dispersed target population and a challenge for the agencies responsible for distributing the messages. In the absence of complete data, public health officials needed rapid interpretation of the available data, coordination among the various agencies in performing this interpretation, and consistent messaging to the public and policy makers.
Environmental justice was a profound concern in New Orleans. As the media pointed out, the suffering in the aftermath of Hurricane Katrina was not equally distributed among the different subpopulations in the city. Vulnerability was
greater among poorer populations and populations of color, who composed a large part of the New Orleans population. Furthermore, exposures in neighborhoods inhabited by vulnerable populations, the toxic exposures that they may have sustained, and their access to services afterward (ranging from evacuation to shelter provision) were different from those of other residents.
Short-Term Environmental Health Concerns
A wide range of environmental health issues surfaced in the aftermath of the hurricane. Even though public health concerns are important to all in government, they are not the only concerns, noted Frumkin. NCEH/ATSDR had to confront a number of crosscutting social and organizational challenges in trying to address the health, safety, and environmental problems following Hurricanes Katrina and Rita. In the lifesaving phase of the response, some immediate decisions had to be made. Identifying and addressing life-threatening environmental hazards and getting them under control was a top priority. Medium-term decisions included controlling hazards so that people could reenter the city. Long-term questions include environmental health considerations in reconstruction.
Unwatering—that is, draining of the floodwaters—was one of the first environmental concerns that people faced after Hurricane Katrina. When people try to reach destinations within the city where transportation and emergency medical services are completely impeded by water, unwatering becomes a health and safety issue.
Potable water was the next concern; people need water for hydration, food preparation, and washing. The instructions that people in the area were given after Hurricane Katrina about washing after contact with sewage water presupposed the availability of clean water, said Frumkin. Having potable water available depends on a functional water treatment facility and intact distribution systems. The disruption that followed the flooding may have interrupted the distribution system as well. That is a potentially complicated issue because infiltration of the distribution system by floodwaters may not only contaminate the inside of the distribution systems but also change the ecology and the biologically active layer of film that lines the water pipes. Once the water distribution system comes back online, it needs to be carefully inspected. Homes with wells have an additional set of concerns above and beyond those of homes that are on public water systems, noted Frumkin.
Sewage was another environmental concern. The availability of sewage treatment depends on treatment facilities and on an intact collection system. Initially, after the hurricane, there was concern that if people reentered their homes and flushed the toilet and the contents went down, that might be reassuring to them that the sewage system was actually working. There was no guarantee, however, that the sewage was in fact flowing to the sewage treatment plant to get treated, noted Frumkin. Interruptions in the collection system could have resulted in sew-
age being discharged into the street. Furthermore, if enough pressure built up, sewage could flow upward instead of downward from the toilet, and that would be very alarming. Raw sewage going into the river is an important environmental and health issue. Septic systems are an additional issue, because when the ground is completely saturated, a septic system does not work well. Most homes across the Gulf Coast with septic systems have that concern.
Energy is central to modern life and often is taken for granted. The lack of energy, the disruption of supplies, and the need for alternative means of generating energy can be important health and safety issues. Electricity is the backbone of energy functioning; it provides, among other things, refrigeration, air conditioning, and functioning traffic lights. Without this critical resource, food can spoil, heat-related deaths can occur, and increased motor vehicle accidents may happen at intersections. Often following disasters, people rely on generators as a means to produce electricity. Similar to other disasters, improper use of generators after Karina resulted in a number of carbon monoxide poisonings in the Gulf Coast (Figure 4-1).
Environmental health issues are very complex, relating to each other in very intricate, weblike ways. Water is interrelated with food, electricity is interrelated with safety, and so on. The interrelations operate on a very diverse set of time scales, spatial scales, and organizational responsibilities. These aspects of environmental health add complexity to the organizational response, said Frumkin.
Environmental health issues are very complex, relating to each other in very intricate weblike ways.
Animals can cause environmental health concerns during disasters in three different ways: (1) insect vectors may proliferate, particularly mosquitoes, as their reproduction rates increase when excess water and heat are present; (2) vermin may be driven from lower ground to higher ground to follow their food sources; and (3) when domestic animals go without food for several days, they may begin to act in a pack fashion to attack people. Theoretically, this can become a health issue, said Frumkin. The insect vector issue was of special concern in Louisiana because, according to national data, prior to Hurricane Katrina the state had confronted West Nile virus at fairly high levels. The majority of the West Nile diagnoses preceded the hurricane by several weeks, but it was enough to raise concern that in the aftermath of the storm further cases of West Nile could occur (Figure 4-2). This concern was one of the reasons for very rapid attention to spraying to minimize and control the mosquito population.
Long-Term Environmental Health Issues
As the region comes back to life, the short-term issues will be replaced by longer-term and more complex issues involving food, transportation, and debris. Following a disaster of this magnitude, one of the public health practice challenges is how to inspect all the food service establishments, including commercial suppliers and institutional settings. This inspection requires a deployment of a large workforce of public health sanitarians to ensure that the food preparation conditions meet health standards.
The quantity of solid waste and debris after the hurricane was unmatched compared with other disasters, said Frumkin. Large quantities of debris and the possibility of contaminants, such as lead paint in older houses, asbestos, and other hazardous materials, will be a long-term challenge. DHHS, EPA, and state and local officials recognize that there may be a number of potential sources of toxic chemicals in the area, such as underground storage tanks, industrial facilities, waste sites, and homes and small businesses that had stocks of hazardous chemicals in them.
The initial medium of exposure
Typically, we approach environmental health risks by using risk assessment. In the case of the Hurricane Katrina aftermath, it is very hard to adapt risk assessment thinking because this event has no precedent.
pathways to these hazardous chemicals is through water. As water dries up, sediment is left; as sediment dries up, dust is left; and as the dust gets airborne, particulate matter is left. Therefore, the medium can change over time, and the ways to approach, measure, and control it will change as well, noted Frumkin. Typically, we approach environmental health risks by using risk assessment. In the case of the Hurricane Katrina aftermath, it is very hard to adapt risk assessment thinking because the exposures for an event of this magnitude are without comparison.
According to Frumkin, currently there are a lot of data on sampling toxic chemicals. EPA undertook a very large sampling program in which such toxins as volatile organic compounds, semivolatile organic compounds, total metals, pesticides, herbicides, polychlorinated biphenyls, and bacteriological contaminants were sampled. EPA posted the findings of the sampling on its website.
Buildings posed a very important set of environmental concerns that got the most attention in the immediate aftermath of the hurricane, noted Frumkin. When a building is deluged with water for some time, two major concerns result: (1) The structural integrity of the building may be damaged and the building may collapse, and (2) in a warm climate, mold will develop. Mold will continue to be problematic, and much of the knowledge available about human responses to mold has resulted from relatively moderate levels of exposure, said Frumkin. Scientists will have a great opportunity to research and learn about exposures that
are considerably higher than usual. In addition to residential buildings, special attention will need to be given to schools and health care facilities because of the vulnerable populations who use those buildings.
A View Toward the Future
The reconstruction and urban planning of New Orleans will raise large-scale questions. It will be important to know how the levees are going to be reconstructed, what will happen to the topography of the city, and how safe the city is going to be for living. Many people have called for the development of healthy urban design, both in New Orleans and in other cities along the Gulf Coast. People have argued that this is an opportunity to create some of the healthiest, most progressive cities of the 21st century, noted Frumkin.
Governor Haley Barbour of Mississippi convened a large group of new urban planners who, focusing on
Reconstruction provides an opportunity to design a city with an active living environment in which walking is greatly encouraged and people drive less and get more physical activity. Now is the time to help promote the public health of the people of New Orleans, changing the Mardi Gras to the Mardi Svelte.
Gulfport and Biloxi and some smaller towns, have put forward a number of suggestions for the healthy design of those cities. Reconstruction provides an opportunity to design a city with an active living environment, in which walking is greatly encouraged and people drive less and get more physical activity. Now is the time to help promote the public health of the people of New Orleans, changing the Mardi Gras to the Mardi Svelte, said Frumkin. This would include rebuilding communities in ways that are environmentally friendly and use fewer resources, which would in turn create less air and water pollution, promoting public health. Adequate and affordable housing is needed in every city in the country, and New Orleans, Gulfport, Biloxi, and other cities are no exception. Healthy housing, an important public health goal, presupposes an adequate supply of decent, affordable housing; housing, especially an affordable housing supply, therefore matters a great deal to those lower on the socioeconomic ladder, noted Frumkin.
Economic revitalization of the affected areas is important, and that poses questions:
Should rapid reentry or delayed reentry be encouraged?
Should we try to rebuild neighborhoods preserving the history of New Orleans, or should we be thinking about redesigning in accordance with environmental and health concerns?
Should we restore wetlands, as some environmental groups have called for, or should we replace them with urban settlement?
Finally, the public needs to think about the issues of new urban design, urban planning, and architecture paradigms and whether they fit with public health.
PROTECTING WORKERS DURING RECOVERY AND REBUILDING
Workers are the common denominator in all disasters, whether it is the result of a natural phenomenon, an accident, or a terrorist attack. Workers are the first responders who go to the scene to perform rescue and recovery operations as well as get involved in remediation, support, and numerous other related activities, said Max Kiefer of the National Institute for Occupational Safety and Health (NIOSH).
As a component of the national response plan, the federal agencies established the Worker Safety and Health Annex (WSHA), led by the Occupational Safety and Health Administration (OSHA). WSHA is activated in a national response or an incident of national significance to ensure that all federal workers and contractors receive timely, consistent, and appropriate recommendations. In addition, it ensures that exposure assessments are conducted and the results disseminated to protect the workers. Under WSHA, NIOSH responsibilities are specifically to provide technical support and expertise in the characterization of complex, unknown, and multiple-contaminant worker exposures and to collaborate in all areas so collective safety and industrial hygiene assets produce consistent, vetted advice to the incident command structure. WSHA’s top priorities are to identify the highest-risk groups and to provide timely and concise recommendations to keep workers free from injury. To understand the exposures and provide recommendations in the Hurricane Katrina response, NIOSH dispatched teams of industrial hygienists and medical epidemiological personnel to work closely with the state and local groups, said Kiefer.
Environmental Exposures of Workers Post-Katrina
Hurricane Katrina caused difficulty in providing services and support from an occupational safety and health standpoint because of the size and nature of the event. Even though people focused on New Orleans, the entire region needed support, noted Kiefer. There was an influx of many workers—some of them undocumented—and employers to the region due to work availability. These individuals needed to be a part of the NIOSH response plan.
In addition, one of the largest post-Katrina challenges for NIOSH was that many workers coming to the region were performing tasks that they were not trained to perform. The NIOSH priority was to identify those at highest risk and ensure that they were protected from getting hurt at work, a task complicated by
the organizational difficulties, the large geographic area affected, and communication problems. The approaches for ensuring safety were different depending on the responsibility of the job. There were workers in the field who were responsible for debris removal and for the levee infrastructure, industrial rebuilding, and environmental cleanup. NIOSH was concerned about workers’ exposures to the sediment, heat, noise, mold, and other environmental harms. Workers who were helping with residential refurbishment and were removing mold or debris were potentially being exposed to asbestos or lead in some of the buildings.
Exposure characterization was challenging because of the size of the affected region and the variability in the environment. Exposures in certain areas of the city may not be consistent with exposures in other areas of the city or other areas of Louisiana. It was hard to generalize the NIOSH characterizations of how someone was conducting debris removal or mold remediation or refurbishment. These may have differed because of the various methods used to accomplish the task, which depended on the work crew, the resources, and the magnitude of the task. Thus, hazard assessments or control recommendations may not have been applicable to all situations (Figure 4-3).
To aid in evaluating workers’ exposure to the contaminants in the soil sediment, NIOSH initially used the EPA’s environmental data to determine which metals and contaminants were in the sediment and where the highest concentrations were as well as to compute what the airborne exposures would be at worst-case airborne levels, such as nuisance dust levels of 10 mg/m. This information was then compared with what would be an occupational exposure limit or minimal risk level, if one existed, from an inhalation standpoint. This modeling enabled NIOSH to obtain hypothetical exposure levels. It also helped to assess whether there was evidence to suggest that high levels of contaminants in the dust would indicate a significant inhalation concern. The computations showed that arsenic, lead, manganese, chromium, and other contaminant levels were below the OSHA permissible exposure limits for particulates not otherwise regulated (nuisance dust). Kiefer cautioned that there are limitations to this approach, and scientists need to stay vigilant, to continue to collect data, and to not rely on this type of modeling as the sole source of information for decision making. As the recovery continues, the exposure to silica during the levee rebuilding will be a concern.
In addition to the above-mentioned occupational exposures, workers are exposed to physical hazards such as heat stress and noise. Initially, when workers were sent to the region affected by Hurricane Katrina, they were put into protective gear because of concerns and uncertainty about the contaminants that might be encountered. For some of the workers, these protective ensembles caused heat stress. After additional data were analyzed, it became clear that some of the tasks did not require protective gear or could be controlled by alternative means, such as engineering controls. Thus it was possible to make selective downgrading of protective gear for some tasks. This decision underscores the need for continued monitoring during disasters to protect workers’ health, allowing for revision of guidelines when warranted. It was difficult to extrapolate the NIOSH exposure data to all situations.
Work practice, training, and risk communication were also challenging, noted Kiefer. Information about how to do things safely and correctly and what protective equipment to wear to do the job was readily available; however, getting that message out concisely and making sure that it was accurate from a scientific standpoint and communicated correctly and consistently were difficult, noted Kiefer. NIOSH provided information, screening recommendations, training, and outreach through job fairs, presentations, participation in community meetings, and working with contractors and other federal partners.
Psychological stress was another significant hazard among the recovery workers and first responders, said Keifer. The New Orleans Police and Fire Departments as well as all those workers involved on the front lines were under a significant amount of stress due to extended shifts and continuous work without
time off. Workers getting hurt from accidents were an additional concern. These incidents mainly consisted of trauma, lacerations, falls, trips, electrocutions, and the like, said Kiefer.
CLEANUP, EXPOSURE GUIDELINES, AND ENVIRONMENTAL POLICY DURING DISASTER: LESSONS TAKEN FROM THE AFTERMATH OF THE WORLD TRADE CENTER ATTACK
To understand what exposure is, we need to define it, said Paul Lioy of the Environmental and Occupational Health Sciences Institute at Rutgers University. Exposure can be an event that is short, long, continuous, or periodic and that affects many subgroups of the population. The response strategy to an exposure cannot be the same for all types of events. In order to plan effectively for an event, a menu with a set of resources as well as scenario development is needed prior to thinking about a response.
When responding to an event, a determination needs to be made whether priority should be given to an acute
When responding to an event, a determination needs to be made whether priority should be given to an acute exposure or to long-term consequences.
exposure or to long-term consequences. According to Lioy, scientists can apply some lessons learned from the terrorist attacks of 9/11 to the post-Katrina response. The 9/11 event can be divided into four exposure categories: (1) within the first hours, (2) within the first 3 days, (3) over the next 12 days, and (4) the time after the first 3 categories. During 9/11 all the exposure categories were mixed together; people were thinking about everything at the same time, and no one understood what was happening. Today things are different: The country is beginning to be able to address acute events, yet scientists will need resources to address complex events such as 9/11 and Hurricane Katrina, noted Lioy. Understanding the difference and needs for acute and long-term events requires further discussion.
After 9/11, the largest environmental exposure that occurred within the first three months was indoor environments contaminated with dust. Many individuals working in this environment were either not wearing respirators or were using them incorrectly. People involved in post-Katrina recovery need to protect themselves by wearing respirators indoors or near open burning fires because of the potential for developing respiratory diseases such as asthma. According to Lioy, dust filled with different contaminants may be an issue in the entire region affected by Hurricane Katrina. Biological toxins and by-products of mold will be there as well. For the housing stock, the question becomes whether to use the strategy of demolishing and rebuilding or salvaging buildings that are salvage-
able. These decisions need to be made to ensure that the recovery is responsive to the needs of the community and to protect the health of workers and the public.
Another issue related to 9/11 was a dust plume that developed after the event. To determine the exposures, researchers reconstructed the event to understand how the plume may have affected workers’ and residents’ health. Modeling helped to decide where the second or tertiary cleanup needed to be done and ensured that everyone was taken into account. For example, workers and people at ground zero were the most affected. As a follow-up, the EPA’s Council of Environmental Quality Expert Technical Panel on the World Trade Center is planning a series of samplings to be done in Brooklyn, which was not initially captured.
With both 9/11 and Hurricane Katrina, a number of people were exposed to material in an environmental medium,
With both 9/11 and Hurricane Katrina, a number of people were exposed to material in an environmental medium.
noted Lioy. The primary difference, however, was that with advance warning about the approaching hurricane, many potentially affected people were evacuated prior to landfall. The individuals who stayed behind were housed in the Superdome or on higher floors of buildings, which confined them in a small space and magnified rather than eliminated the problem of survival; it also increased the potential for infection and disease.
One of the lessons learned from 9/11 was that some exposures could not be measured because of the unexpected nature of the event and the lack of available trained personnel. The potential exposures could not be measured, and thus respiratory illnesses could only be estimated. The dust after 9/11 was very unusual. It was a complex mixture of toxins that individually may not have been harmful; however, synergistically they may prove to be problematic. A similar situation could appear in the post-Katrina region once the sediment dries and becomes dust. There might be multiple toxins and biological materials that act individually or synergistically to produce adverse health outcomes. It is therefore very important to characterize these toxins and materials well and ensure that when people go back to their homes and workplaces, they know what they may be exposed to so that they can protect themselves.
Air quality and water quality need to be monitored in the region affected by Hurricane Katrina, and it is important to focus on the right chemicals. Even though ozone is an important pollutant, measuring it as a primary air pollutant is ineffectual in terms of rehabitation. After 9/11, EPA measured many air pollutants, and it was satisfying to see the air quality improve as time went on, said Lioy. This trend is very important for populations who are thought to be at risk. In response to Hurricane Katrina, we need to ensure that the quality of the water
and air is measured consistently and that the information is readily available to everyone who is looking for the data.
Lioy highlighted the following areas in which further research and discussion need to occur in order to address large-scale disasters:
While the country is beginning to learn to address acute events effectively, first responders, policy makers, and researchers need to continue to learn from large-scale, complex disasters how to develop effective strategies to respond to acute events.
Strategies need to be put in place to obtain accurate exposure data as an event is unfolding. This is particularly challenging when the disaster is unexpected, such as 9/11, and there is a lack of trained personnel to perform monitoring. Nonetheless, scientists need to begin these discussions and plan for monitoring while a disaster is not occurring, not as the event is happening.
Although exposure guidelines are available, there are no guidelines that effectively address acute exposure levels or routes of exposures that are experienced during a disaster.
First responders and recovery personnel—those in charge of cleanup—need to be trained to use respirators correctly.
Before allowing people to return to their homes and workplaces, researchers and policy makers need to consider the variety of toxins and their potential to act synergistically in order to provide guidance so that individuals can protect themselves.
Many issues still exist with exposure standards, said Lioy. There are no acute exposure guidelines that effectively address different disasters. One of the main questions is still how safe is safe and how bad is bad. There isn’t reliable information for acute exposure responses because standards appropriate for reentry and for approving the safety of living in a post-disaster community have not yet been developed. EPA has started developing the standards, which are called Acute Exposure Guidelines. However, biological agents and more chemicals need to be added to the guidelines to ensure the most effective approach in short-, medium-, and long-term risk assessments. It is imperative that this is done and done well, noted Lioy.