A Message from the Commissioner of the New York City Department of Health and Mental Hygiene

The September 11 terrorist attacks affected millions and caused physical and mental health conditions for thousands of people most directly exposed to the disaster. For nearly two decades, the federally funded NYC Health Department WTC Health Registry has studied the long-term effects of the attack on area workers, residents, and students and the rescue, recovery and clean-up workers who responded. The Registry’s research enables health care providers and policymakers to respond health concerns, address gaps in care, and plan for future disasters.

What We Know

Because of the Registry’s work, we know that the majority of people exposed to the WTC attack are healthy and symptom free, but thousands of those most directly exposed have one or more chronic health conditions.

Post-traumatic stress disorder

Symptoms of post-traumatic stress disorder (PTSD) are the most common health effect of the 9/11 attacks.

  • Up to 20% of adults directly exposed to the disaster or injured in the attack had PTSD symptoms 5 to 6 years after the attack; this is four times the rate in the general population.
  • Risk factors for PTSD were intense exposure to the dust cloud
    • injury
    • being on a high floor at WTC
    • evacuating late
    • working for an employer that experienced loss of life,
    • witnessing horror,
    • knowing someone who was killed in the attack,
    • event-related job loss,
    • having little social support.
  • Rescue and recovery workers who got to the WTC site on or soon after 9/11 were more likely to develop PTSD than those who arrived later. The longer someone worked at the site the greater the risk for PTSD.
  • Rescue and recovery workers from non-emergency occupations such as construction and sanitation workers also suffered higher rates of PTSD than emergency responders.
  • People who experienced trauma before or after 9/11, such as losing a job after the attacks, or urban or domestic violence, were at increased risk for developing PTSD.
  • Ten years after the attack, 15% of Registry enrollees had PTSD symptoms. PTSD was more likely to persist or get worse in people who were unable to get mental health treatment, had high 9/11-related exposure, were unemployed, or had little social support.
  • http://www.ncbi.nlm.nih.gov/pubmed/26603700


  • Ten years after the attacks, 15 % of Registry enrollees reported depression and 10% reported both depression and PTSD.

Alcohol Use

  • Five to six years after the attacks, people who had the greatest exposure to the events of 9/11 or who had 9/11-related PTSD were about twice as likely to drink four to five drinks at a time (binge drinking).

Tobacco use

  • Smokers with mental health conditions are less likely to quit smoking, and may need additional support to do so.


  • Within 6 years after 9/11, one in ten Registry enrollees developed asthma-- three times the national rate.
  • The risk for asthma was higher for rescue, recovery, and clean-up workers; residents who didn’t evacuate their homes; residents and office workers who returned to homes or workplaces covered with a thick coating of dust; and people who both lived and worked in lower Manhattan after 9/11.

Lung function

Lung function describes how well a person can move air in and out of the lungs.

  • Firefighters and emergency medical service (EMS) workers experienced sharp declines in lung function within a year of the attack. Ten years after 9/11, these changes were largely the same, even in even those who never smoked.
  • Six to seven years after 9/11, four times as many firefighters and twice as many EMS workers had below-normal lung function for their ages, as before the attacks. Lung function declines were greater for current smokers than for non-smokers.
  • Changes in lung function also affected area workers and residents.

Respiratory symptoms

  • Ten years after the WTC attack, lower respiratory symptoms (LRS) such as coughing, wheezing, trouble breathing, or using an inhaler still affected rescue and recovery workers, area residents and workers, and passers-by. Half of those with persistent LRS also had PTSD, depression, or generalized anxiety disorder.
  • Respiratory illness and mental health conditions often occur together in people exposed to disaster.

Heart disease

  • People who suffered more than one injury on 9/11 and have 9/11-related PTSD are three times more likely to develop heart disease as people who weren’t injured and didn’t have PTSD.
  • Male rescue and recovery workers are at higher risk for subsequent heart-related hospitalization.

Infant, child, and adolescent health

  • Very young children who were caught in the dust cloud on 9/11 are at increased risk for developing asthma.
  • Six to seven years after 9/11, adolescents who were exposed to WTC at ages 5 or older were at increased risk for behavior problems.
  • Babies born to mothers with exposure to 9/11 and PTSD had a higher risk of low birth weight and to be born pre-term.

What More We Can Learn

The WTC Centers of Excellence and the WTC Health Registry offer medical providers and researchers information that over time, will help determine the full extent of WTC-related conditions, how long they last, and if any new conditions appear. Their work will help answer questions about long-term effects of the disaster

  • Potential WTC-related cancers:Since cancers typically develop slowly, more research is needed to determine if these early study results will remain the same or change over time.
    • Prostate and thyroid cancer: Rates among nearly 21,000 rescue and recovery workers enrolled in the WTC Health program were higher than overall rates in New York, New Jersey, Connecticut and Pennsylvania, where the majority of workers lived.
    • Cancer in firefighters’ cancer: The NYC Fire Department found that cancer risk among nearly 9,000 firefighters with WTC exposure may be at greater risk for cancer than those who weren’t exposed.
  • Which WTC-related conditions are being treated and how well the treatment works.
  • Health care needs of people not receiving care for WTC-related conditions coverage gaps remain
  • The role that WTC-related illness may play in heart disease, diabetes, heartburn, and reflux disorders.
  • Extent of WTC-related depression and substance use are among WTC-exposed populations.
  • Effect of ongoing WTC-related health conditions on long-term mental health.
  • Long-term effects of 9/11 on children who went to school or lived in the area, whose parents were part of the rescue and recovery effort, or who lost family members.
  • Health impact of subsequent disasters and events, such as Hurricane Sandy, on people with 9/11-related conditions, including PTSD.

The WTC Health Program--Help For Those Affected By 9/11

If you were affected BY the 9/11 attacks you may be eligible for free treatment and medication through the World Trade Center Health Program at one of the New York City WTC Centers of Excellence or the National Provider Network. Call 1-888-982-4748 or visit the WTC Health Program for more information.

The World Trade Center (WTC) Health Program is a limited federal health program administered by the National Institute for Occupational Safety and Health. The Program provides no-cost medical monitoring and treatment for certified WTC-related health conditions to those directly affected by the 9/11 attacks in New York, the Pentagon, and in Shanksville, Pennsylvania.

The Program also funds medical research into physical and mental health conditions related to 9/11 exposures.