PROTECT Study Examining the Long-Term Impact of Hurricane Maria on Water Quality and Human Health in Puerto Rico Selected as NIEHS Paper of the Month

The safety and long-term sustainability of drinking water is a global public health priority that has been challenged by both regulated and emerging anthropogenic contaminants. Maintaining drinking water security is further challenged as intense hydrological events like hurricanes and droughts become more frequent and cause changes to water supplies that are not always fully understood.

To better understand how hydrological events affect drinking water quality in the long-term, Dr. Lin and co-authors conducted a 14-month island-wide assessment of drinking water quality following Hurricane Maria, which impacted the island in September 2017. Researchers used an innovative integrated approach that included the targeted analysis of 200 emerging micropollutants and 22 trace elements.

In their analysis, researchers observed that the concentrations of 11 trace elements and seven organic micropollutants decreased in samples taken from March to November 2018 (more than six months after Hurricane Maria) compared to samples taken within five months post-hurricane. This demonstrates that Hurricane Maria had a strong but short-lasting impact on the occurrence of these 18 contaminants. This also indicates that there was at least a partial recovery of Puerto Rico’s tap water quality six months after Hurricane Maria. Conversely, researchers observed seven trace elements and ten micropollutants with higher concentration levels in samples taken more than six months after Hurricane Maria compared to samples taken within five months post-hurricane. Researchers believe that this indicates that these specific contaminants were continuously entering tap water from sources or events that were different from Hurricane Maria.

An additional component of this research was an analysis of similarities (ANOSIM) to investigate potential differences in detected contaminant levels across the different regions of the island. Results demonstrated significant spatial variations of contaminant concentrations between northern and southern Puerto Rico, with residents in northern Puerto Rico at a higher risk for long-term exposures to tap water contaminants at elevated levels following Hurricane Maria. Notably, this region is also the home of eight Superfund sites.

To understand how the movement and release of pollutants during Hurricane Maria may have impacted molecular activity and human health, researchers also conducted a molecular toxicity evaluation. The evaluation showed that the accelerated release of certain pesticides and pharmaceuticals and personal care products (PPCPs) by the hurricane may have increased certain cell-level toxicity effects for more than the six months after the hurricane. This increased toxicity could be linked to adverse health outcomes like inflammation, impaired reproductive systems, and organ toxicity. Even though levels for certain contaminants had decreased back to normal levels six months after Hurricane Maria, the human health effects may persist and be felt for much longer.

This integrated research demonstrates a potential link between major hydrological events, elevated tap water contaminant levels, and long-term adverse health outcomes. These findings emphasize the importance of continuously monitoring drinking water exposures for prioritized contaminants, especially in risk-prone areas, following events like Hurricane Maria, as well as the necessity of understanding exposure-effects relationships. Furthermore, researchers believe it is important that health-based epidemiological data be more readily available because it may contribute to better post-disaster drinking water quality and resource management.

Read the full paper here.