NewYork-Presbyterian. The University Hospital of Columbia and Cornell.

-- It has been five years since the terrorist attacks of Sept. 11, 2001, and many who were directly affected by the tragedy carry unpleasant reminders in their minds, hearts, and even their lungs.

Thousands of workers who toiled for months on the smoldering pile that was Ground Zero continue to complain of respiratory illness, including a chronic, soot-laden hacking known as "World Trade Center Cough."

At the same time, scientists are monitoring the development of hundreds of children, born early and underweight, to families living in Lower Manhattan.

Respiratory Effects of Toxic Soup Common

The potential cost of treating the long-term health effects of 9-11 is daunting. Most pressing are the needs of 40,000 first-responders and clean-up workers who experts say inhaled a toxic soup of lead, mercury, dioxin, asbestos, benzene, and other contaminants from the debris of the collapsed towers.

New research released last week by Mount Sinai Medical Center in New York City found that 69 percent of these workers developed new or worsened respiratory symptoms after working at the site, with 59 percent still showing evidence of symptoms today. Those who arrived first on the scene tended to have the worst symptoms, the researchers say.

"It wasn't surprising to me to see these effects from a toxic exposure that goes on for that length of time, even for several days or weeks, with deposition of metals in the lung and no way for the lungs to clear it," Dr. Len Horovitz, a pulmonary specialist at Lenox Hill Hospital in New York City.

Dr. Horovitz adds that things could possibly get worse for some of those affected, especially in terms of the long-term risk for cancer for those who were exposed.

Psychological Trauma Improving with Time

The terrorist attacks on the World Trade Center and the Pentagon also left many Americans across the country with deep and lingering emotional scars.

A team led by Dr. David Spiegel, a professor of psychiatry at California's Stanford University, conducted surveys of New York City residents in the six months after the attacks.

"Initial rates of post-traumatic stress disorder (PTSD) involved large proportions of the population," Dr. Spiegel says. "We found that 7.5 percent of people in the New York City metropolitan area initially met criteria for PTSD, and 20 percent of people south of Canal Street - right where the WTC is - met the criteria."

While studies on national rates of PTSD following 9-11 have not been done, "our research shows that just witnessing somebody else getting injured or killed can induce PTSD-like symptoms," he says. That includes witnessing horrific scenes via television, the Stanford expert says.

But there is some good news, he notes.

The number of people with symptomatic PTSD linked to 9-11 has subsided over time, he said. People who were less isolated and able to talk over their fears and feelings with others tended to recover more quickly, he adds.

Effect of Stress and Pollutants on Babies Unclear

The jury is still out, however, on the youngest potential victims of the attacks.

Beginning soon after the disaster, a team led by child health expert Dr. Federica Perera, of Columbia University's Mailman School of Public Health, has tracked the birth outcomes and long-term development of more than 300 babies born to women living near the site. All of the women were at some stage of pregnancy on Sept. 11, 2001.

"Babies born to women who had been living with a two-mile radius of the World Trade Center site during the months following 9-11 weighed significantly less at birth - about a third of a pound less - compared to infants born to other women living further away," Dr. Perera says. The study also found that nearly all women, regardless of their proximity to the site, gave birth slightly earlier than usual - probably the result of an increase in stress linked to 9-11.

However, the tendency toward smaller birth weights continued even after Dr. Perera's team adjusted for this prematurity. "So, we infer that there was [also] a potential effect of the pollutants themselves," she says.

Blood tests on newborns' umbilical cords confirmed relatively high levels of combustion-linked toxins called polycyclic aromatic hydrocarbons (PAHs) in babies born to mothers living in Lower Manhattan, she adds.

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