The story of Hurricane Harvey typically begins with a number: 51. That is the amount of rain, in inches, that the storm dumped on our region over four days in August. But the historic rainfall and flooding are only part of the Harvey story. The storm resulted in untold exposures to chemicals and other threats to human health. Nine months later, we still do not know the full extent of Harvey\u2019s toll on people\u2019s physical and mental well-being. That is why the Houston Health Department, Harris County Public Health, Environmental Defense Fund and Rice University want you to enroll in the Hurricane Harvey Environmental Health and Housing Registry (harveyregistry.rice.edu). Whether you were flooded or not, enrolling in the registry will assist officials in tracking health and housing problems and identifying vulnerable communities, with the goal of developing tailored interventions to help people in the Harvey-affected areas. We modeled the project after the World Trade Center Health Registry, which tracks tens of thousands of people who were exposed to fire and smoke in Lower Manhattan in the aftermath of 9\/11. The WTC registry data continues to provide valuable insights. For example, adults who were near the WTC around the time of the terrorist attacks are more likely to have cancer than the general population. Asthma and post-traumatic stress disorder also are more prevalent among adults who lived near the disaster site. Analyses indicate that women, people of color, and those with low incomes have higher rates of both physical and mental health problems. It is our hope that we do not find any long-term problems in our community. However, there is no doubt that Harvey had wide short-term health consequences. Doctors, for example, worried that the storm produced coughs and other ailments that for some people have yet to go away. Harvey impacted oil refineries, chemical plants, Superfund sites and waste treatment plants, fouling air, water and soil. It also left behind new threats in homes, like mold and bacteria. In all, the media reported that more than 100 Harvey-related releases of harmful chemicals occurred in the Houston\/Harris County area. While much attention focused on a chemical plant explosion in northeast Harris County, there were 10 larger releases of air pollutants due to storm damage, an Environmental Defense Fund analysis found. To develop the most complete picture of people\u2019s health after Harvey, we urge you to enroll in the registry, even if your neighborhood was not flooded. The voluntary survey, found at harveyregistry.rice.edu, takes about 10 minutes to complete. Information provided can help us to identifywho was - and continues to be - at risk from the storm. We will combine basic health and housing information provided by those who enroll in the registry with all available environmental exposure and social stressor data. Ideally, what we learn will lead to action. For example, communities could use the data to secure funding for school-based or neighborhood-based asthma intervention programs. The data also could inform public officials as they develop new plans and policies to protect our community before the next storm. We may reach out to you in the future to learn more about your experience, but you will be under no obligation to respond to future inquiries. It will be in every sense of the word a partnership among public health officials, researchers, and the community we serve. If you lived or worked in the region during Harvey, you are eligible to participate in the registry. The more people who register, the greater impact the project can have. With the new hurricane season upon us, we remember how our community came together to support those who lost so much during the storm. Ultimately, it is in our collective best interest to learn from what happened with Harvey to help all of us build a healthier and more resilient community. The registry helps us do just that. Persse is the city of Houston\u2019s public health authority and physician director of its emergency medical services. Shah is the executive director and public health authority for Harris County Public Health. Craft is senior health scientist at Environmental Defense Fund, and Miranda is professor of statistics and provost at Rice University and the Hurricane Harvey Registry\u2019s principal investigator.