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Looking for lingering health effects of Hurricane Maria

A year after the storm, scientists are trying to gauge the long-term impact on water and air quality

by Deirdre Lockwood, special to C&EN
September 17, 2018 | A version of this story appeared in Volume 96, Issue 37


Photo of Ingrid Padilla with the Puerto Rico flag in the background.
Credit: Erika P. Rodríguez
Hydrologist Ingrid Padilla is monitoring water for organic pollutants that may have been mobilized from Superfund sites during the hurricane.

When Hurricane Maria hit Puerto Rico last September, Ingrid Padilla, a hydrologist at the Mayagüez campus of the University of Puerto Rico (UPR), spent a full day sheltering inside her home in the mountains of Mayagüez. The next morning she stepped out to devastation. “When I came out it was something surreal,” she says. “It seemed like a fire went through.” Water and power utilities were out—it would take her until December to get running water back and until February to get electricity. She spent the next few days in “survival mode,” she says, gathering supplies and making sure her neighbors were all right.

The storm’s severity, coupled with an insufficient response by the U.S. government—as acknowledged in a recent report by the Federal Emergency Management Agency—proved catastrophic. According to a revised death toll released by the Puerto Rico government on Aug. 28, nearly 3,000 people died because of the hurricane. Going forward, Padilla and other researchers are concerned that the storm’s effects may also threaten the health of surviving residents on a longer-term basis through exposure to tainted water and air.

In the days after the storm, Padilla noticed people harvesting water from their roofs to store for sanitation or drinking. Some tried to disinfect it by dumping bleach into storage jugs. As a hydrologist she cringed, thinking of all that might be in the water—bat and bird droppings, elevated levels of bacteria, and products of bleach reactions.

Others without running water tapped additional potentially dangerous sources of water for sanitation and drinking—most troublingly, a well in Dorado that drew water from an area designated by the federal Environmental Protection Agency as a Superfund site, a zone needing extensive hazardous waste cleanup. Past testing had shown it contained tetrachloroethylene and trichloroethylene, the Washington Post reported. Those industrial solvents are linked to health problems, including cancer, and negative consequences for the liver, kidneys, and immune and reproductive systems.

Map showing locations of Superfund sites and the path of Hurricane Maria over Puerto Rico.
Credit: C&EN/Shutterstock
Industrial contamination
Puerto Rico is home to 18 Superfund sites needing significant hazardous waste cleanup. During Maria, hurricane-force winds spanned the island, and some areas received as much as 50 cm of rain from Sept. 17 to 21, 2017. Flooding may have exacerbated aquifer pollution from the Superfund sites.
Source: U.S. Environmental Protection Agency

Since 2010, Padilla has been investigating chemical contamination of drinking water supplies by Superfund sites along Puerto Rico’s northern coast, a major industrial area. Her work is part of a large collaborative project focused on the relationship between this contamination and high preterm birth rates in Puerto Rico. The project is called Puerto Rico Testsite for Exploring Contamination Threats (PROTECT) and is funded by the National Institute of Environmental Health Sciences. Years before the hurricane, Padilla documented the contamination of the region’s aquifers—as well as tap and well water—with industrial chemicals, including trichloroethylene, other chlorinated volatile organic chemicals, and phthalates such as di-2-ethylhexyl phthalate. Elevated phthalate exposure in pregnant women has been linked to a greater likelihood of preterm birth.

Padilla wondered whether the hurricane floods had further mobilized some of these pollutants to contaminate drinking water in the area. But given the storm’s devastation, it took a month before she was able to begin sampling tap water in local homes and groundwater.

When she and her team eventually compared the samples they took a month after the storm with those from before the storm, they found that some contaminants had higher levels after the hurricane than before it, though some had lower levels. They have continued to take samples during the past year. “How long is the impact we’re going to see? We don’t know the answer,” especially because the limestone aquifers underlying that part of the island are rife with fissures and sinkholes, she says. Water can flow through the aquifers rapidly, so water quality can change quickly, and soils may not sequester pollutants. Padilla and her colleagues plan to report their full results in the next few months.

Photo of a man using an outdoor water spigot to fill a sample container.
Credit: Alonda Cruz Portillo
Geochemist Benjamin Bostick collected about 100 drinking water samples along Puerto Rico’s northern coast in June, including this one from the only running water at a home and restaurant in Toa Baja near San Juan.

In June, Benjamin Bostick, a geochemist at Columbia University, traveled to the same industrial area that Padilla is monitoring to investigate potential contamination of drinking water by metals, such as lead and arsenic, as a result of flooding near the Superfund sites. He funded the trip himself; he had unsuccessfully applied for a grant from the National Institutes of Health to monitor water after the hurricane. Nine months after the storm, many people he encountered, even those in wealthier households, still didn’t have running water. “I saw things I didn’t quite expect, like people driving Mercedes who didn’t have access to water in their home,” he says. He also visited restaurants without running water. Even people who did have running water reported that the supply was unreliable, he says.

Also, among the people he spoke with, “almost nobody had faith in water quality,” he says. They seemed resigned to that uncertainty, with many choosing to use bottled water if they could afford it.

Bostick took about 100 drinking water samples from homes and shops in locations from San Juan to Arecibo near Superfund sites, in particular a large former battery-recycling facility. He analyzed the samples for lead and arsenic. He also tested for iron, sulfate, and manganese, geochemical indicators of reducing conditions, which can increase the solubility of some toxic metals.

“The water quality actually looked pretty good,” he says. It was generally low in trace metals, with only one sample reaching the U.S. Environmental Protection Agency’s action level for lead. It was also very fresh and oxidized. The results were surprising and hopeful, he says, although they provide a limited picture that shouldn’t be overinterpreted, given how dynamic the groundwater quality is in the region.

Photo of pH and conductivity meters in a person's lap.
Credit: Alonda Cruz Portillo
Geochemist Benjamin Bostick measured water samples’ pH and conductivity in the field in Puerto Rico, then analyzed them back at Columbia University for metals, including arsenic and lead.

Because of the challenge of monitoring water in the aftermath of the hurricane, some of Padilla’s collaborators on the PROTECT project are trying to go beyond water sampling to more directly gauge people’s exposure to potential contamination. Deborah Watkins, an environmental health scientist at the University of Michigan, is examining how stress and chemical exposure during the hurricane may have influenced the health and birth outcomes of women who were pregnant during Hurricane Maria. Previous work by her team links exposure to pollutants—including phthalates, phenols, and parabens—with altered reproductive and thyroid hormone levels during pregnancy. The altered hormone levels in turn may affect birth outcomes and fetal neurodevelopment, Watkins says.

About 100 pregnant women were enrolled participants in the PROTECT project when the storm hit. The project’s research clinic in Manatí was up and running again about two weeks after the storm, an “astonishing” feat resulting from the hard work and dedication of local research staff, Watkins says. Many of the study participants sought out the research clinic after the storm to procure food, prenatal vitamins, water filters, and help contacting loved ones. The PROTECT team took blood and urine samples from the participants at multiple points during pregnancy, resulting in samples collected before and after the storm—a rare trove of information on the health impacts of the hurricane.

Using these samples, Watkins is analyzing the women’s exposure to phthalates, phenols, and parabens, as well as some metals. In addition, she is looking at the women’s exposure to polycyclic aromatic hydrocarbons (PAHs), which are released upon combustion of oil and gas. Watkins hypothesizes that the women may have been exposed to more PAHs after the storm because of the widespread use of diesel and gas generators. Since stress also affects pregnancy and birth outcomes, the scientists also asked women to complete a questionnaire about their experiences during and after the hurricane and to report their levels of stress. The team plans to compare these results and the women’s birth outcomes to those of participants who gave birth before the hurricane.

Though Watkins and her team are just beginning to analyze the samples, she hopes that their eventual findings will identify potentially harmful chemical exposures so that people can make preparations to prevent them in future storms. Through the Center for Research on Early Childhood Exposure & Development in Puerto Rico and other related programs such as Environmental Influences on Child Health Outcomes, she and other researchers also plan to follow children born to study participants after the hurricane to monitor the children’s neurodevelopment from infancy to ages four to five.

Photo of a person holding a flask in a fume hood.
Credit: Erika P. Rodríguez
A trainee from the PROTECT project extracts a sample for analysis of phthalates in tap water at the University of Puerto Rico, Mayagüez.

Like preterm birth, the incidence of asthma in Puerto Rico is higher than the average for the mainland U.S. Researchers don’t understand why, though environmental and genetic factors likely play a role, says Humberto Cavallin, an architecture professor at UPR Río Piedras. After the hurricane, Cavallin suspected that widespread flooding of homes would impact residents’ respiratory health by creating perfect conditions for mold. He was right: The Associated Press reported in June that doctors are seeing many more patients with severe asthma after the hurricane than usual, and the San Juan Aeroallergens Station reported in May the highest levels of mold in over a decade.

Cavallin recently teamed up with microbiologists, engineers, and doctors from UPR Medical Sciences, Larkin University, and the University of Texas, Austin, to examine the relationships among flooding, specific fungi present in homes, architectural design, and people’s respiratory health and stress levels in a project funded by NIH.

Many people’s roofs collapsed or leaked in the storm’s high winds, but water intrusion and damage to homes continued and in some cases worsened after the storm. “For the first six months, almost every other day it rained in San Juan,” Cavallin says. The best solution most people had was to cover their houses with tarps, but even obtaining those took time. “I wish the blue tarps would have got there earlier,” says Juan P. Maestre, an environmental scientist at UT Austin who is part of the project. Even now, a cascade of blue tarps is visible from the air on flights into San Juan, a sign of how long recovery is taking.

In a preliminary study by Cavallin and Benjamin Bolaños of UPR Medical Sciences on homes along the San Juan coast after the storm, the team found high levels of Aspergillus and other fungi associated with allergic reactions, asthma, and other respiratory conditions. Some homes had greater levels of fungi inside the house than outside. These results were unexpected, especially considering that the houses were quite open to the outdoors and had natural ventilation, Cavallin says.

Photo of two people working in dense vegetation.
Credit: Marvic Carmona
About two months after Maria hit, doctoral students from hydrologist Ingrid Padilla’s lab sampled a sinkhole covered by fallen vegetation near Tallonal spring, a source of domestic drinking water in Arecibo.

Some of these houses had noticeable mold or water damage, but others had none. Fungi can grow hidden in furnishings and behind walls, and the paper on the surface of drywall is “perfect food” for them, Cavallin says.

Cavallin and his colleagues continue to monitor 50 homes in San Juan, half of which experienced flooding—some with nearly 3 meters of it—and half of which did not. This summer, they began collecting microbiological samples from air and dust inside and outside the houses. They plan to culture these samples in the lab to screen for live fungi. Then they will sequence the microorganisms to identify them and examine their relationships with the respiratory and mental health of residents, along with the design elements of their houses.

Photo of a group of people behind seven buckets and other equipment.
Credit: Lilliana González
Soon after the hurricane, members of the PROTECT research team disrtibuted water filtration kits and supplies to pregnant women participating in their study and community members in need.

Their results could guide future efforts to make Puerto Rico and other hurricane-prone regions more resilient to future storms. Cavallin stresses the importance of designing and maintaining buildings to withstand high winds and choosing materials that are more resistant to mold, as well as mounting a rapid response to help people dry out their homes. “After 48 hours, everything that’s not dried is prone to develop fungi,” he says.

Ultimately, all these researchers’ work demonstrates the challenge of tracking the environmental and health impacts of a disaster while in crisis mode—which is when some of the most damaging impacts are likely to occur. “We already know the hurricane affected the supply of water and probably water quality, but we really missed our opportunity research-wise to see the bulk of that,” Bostick says.


To ensure better monitoring in the future, Bostick hopes to develop a network of local volunteers who could test water for metals with simple kits regularly over time and possibly respond more quickly after a storm. So far, he has discussed the idea with a group of students and a farmers cooperative in Puerto Rico—“so that come another natural disaster, which is almost certainly, sadly, going to happen at some point, we have some basis for understanding what’s happening under those conditions.”

Deirdre Lockwood is a freelance writer based in Seattle.


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