ATS 2009: Asthma Rates Continue to Soar in New York's Chinatown Children Post-9/11

Kristina Rebelo

May 22, 2009

May 22, 2009 (San Diego, California) — Children who resided in the Chinatown neighborhood of New York City near the World Trade Center (WTC) at the time of the September 11, 2001 terrorist attacks have a higher rate of self-reported asthma than those living farther away, despite being documented in 2000 US Census data, exactly 1 year before 9/11, as having the lowest levels of asthma (6.8%) compared with other New York City (NYC) neighborhoods. The finding was released here at ATS 2009: the American Thoracic Society International Conference.

Dr. Anthony M. Szema

A research team led by Anthony M. Szema, MD, from the Department of Medicine, State University of New York (SUNY) at Stony Brook School of Medicine, reported in October 2004 that there was an increase in the rate of childhood asthma and a worsening in those with pre-existing asthma in a homogeneous Chinatown neighborhood just blocks from the WTC (J Allergy Clin Immunol. 2004;113:420-206).

Their new study focuses on the same area and concludes that asthma rates there are still higher than among other groups residing farther from the area (28% vs the NYC reference rate of 13%).

"This is a clinically relevant study in that these kids need to be diagnosed and treated," lead investigator Dr. Szema told Medscape Pulmonary Medicine before his presentation.

In 2008, 353 parents of children at an elementary school in Chinatown were surveyed in a questionnaire based on the WTC Registry and approved by the NYC Department of Education. Spirometry was conducted on 202 students with parental consent; meanwhile, fine-particulate samplers were deployed on the roof of the school by the New York State Department of Environmental Conservation because Dr. Szema's group considered that urban air pollution could be a contributing risk factor for their study population. Air pollution was measured as the concentration of 2.5 micron-sized particles per cubic meter of air collected in a 24-hour time period (PM2.5). Dust samples from the school were collected, sampled, and analyzed for dust-mite, cat, rat, mouse, and cockroach antigen levels.

Dr. Szema said that his study group's parents informed him that their homes had never been part of any Environmental Protection Agency (EPA) residential cleanup program. A multi-agency Task Force on Indoor Air in Lower Manhattan apparently did not include the Chinatown area when it sent out certified contractors to conduct professional cleaning services at the request of residents or property owners.

Study results found that 28% of all students who underwent spirometry (n = 159) had a forced expiratory volume in 1 second (FEV1) ≤ 80% of predicted normal, not including asthmatics on medications, for a total asthma burden of 42%; among children older than 7 years who were alive on 9/11, 29.2% had an FEV1 ≤75% of predicted levels.

The study reported that although 22% of parents smoked, less than one third of the smokers' children had airway obstruction; 26% of all subjects had reduced forced vital capacity, but only 2 of 159 had an elevated body mass index.

With regard to the air-pollution testing, the concentration of PM2.5 reached a high of 40 μg/m3 (above the threshold of 35 μg/m3), which, according to the authors, is considered acceptable by the EPA; indoor aeroallergen concentrations were found to have been negligible.

A chemical analysis of the inhaled substances after the collapse of the WTC included findings of calcium sulfate and calcium carbonate, compounds that are known upper-airway irritants in humans. In addition to findings of soot, leaded and unleaded paint, plastic, and partially burned jet fuel, other analyses have found inorganic metals, radionuclides, ionic species, asbestos, polycyclic aromatic hydrocarbons, polychlorinated biphenyls, polychlorinated dibenzodioxins, polychlorinated dibenzofurans, pesticides, phthalate esters, brominated diphenyl ethers, and other hydrocarbons.

A study limitation noted by authors was that the study estimated asthma incidence without evidence of reversibility of airway obstruction; researchers were unable to do bronchial dilator tests on their subjects.

"We are currently beginning impedance oscillometry and exhaled breath condensate nitric oxide measurements as more sensitive measures, in addition to serial spirometry," Dr. Szema said. "Our medical students at SUNY Stony Brook have engaged in an aggressive antismoking education program as well for this group.

Dr. Phyllis Dennery

Phyllis Dennery, MD, FAAP, chief of the Division of Neonatology, Children's Hospital of Philadelphia, and professor of pediatrics at the University of Pennsylvania School of Medicine, told Medscape Pulmonary Medicine that there was a debate about whether the findings of increased asthma in this population could be attributed to lung injury in the children. "The FEV findings were about double the NYC rate," observed Dr. Dennery. "There was definitely a chemical signature for the WTC event — a 2-hit hypothesis that this is something caused by lung damage doesn't seem out of the question; when kids get an infection, they could be predisposed."

"This is a huge public-health concern," said Dr. Dennery, calling the study "impressive." She was not involved in the study.

Dr. Dennery asked Dr. Szema if there could be residual particulates in the air as an ongoing insult.

He responded in the affirmative, adding that "these children were exposed to the WTC catastrophe that could have caused initial lung damage, and this damage could be accentuating their response to current exposure to urban air pollution, such as the distance-related effect of the Manhattan Bridge, where we counted 100 diesel trucks per hour."

Dr. Szema and Dr. Dennery have disclosed no relevant financial relationships.

ATS 2009: American Thoracic Society International Conference: Abstract 4986. Presented May 19, 2009.


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