Hazardous Site Health Evaluation Program


Ozone Health Effects Field Study of Children and Counselors at Two Day Camps in New Jersey, July 1988

For the full text of this study, please write to the New Jersey Department of Health, Consumer and Environmental Health Services, PO Box 360, Trenton, New Jersey, 08625-0360.


In the summer of 1988 a field study of ozone health effects was conducted at two summer day camps in suburban-central New Jersey. Respiratory health effects of exposures to daily outdoor ambient levels of ozone were evaluated. This was accomplished by assessing the daily pulmonary function, as measured by spirometry, of a group of outdoor employees and summer day camp children. The study was a cooperative effort between the New Jersey Department of Health (NJDOH), the University of Medicine and Dentistry of New Jersey (UMDNJ) - Robert Wood Johnson Medical School, and the New Jersey Department of Environmental Protection (NJDEP).

The objectives of the study were to: 1) evaluate community exposures to ozone in an outdoor setting; 2) attempt to document health effects to outdoor workers and children; and 3) use this information to develop a rationale for policy setting in the area of ozone risk communication and community outreach.

Thirty-four campers and counselors had daily pulmonary function tests performed each afternoon while attending camp during the month of July. The subjects ranged from 9 to 35 years of age and were evenly divided among males and females. Twenty subjects were of ages 14 and over. The 14 children under age 14 were day campers and attended the same camp. A mobile medical screening van was used to house the spirometric equipment and travel to each camp. Continuous ozone measurements were collected at two locations over the entire study period by the NJDEP.

The summer of 1988 experienced some of the worst episode of ozone air pollution in recent history with recorded high ozone levels during most of the summer. An intense ozone episode was recorded just prior to and during the first two weeks of the study.

A respiratory symptom questionnaire and activity timeline log were administered to the subjects daily. Symptoms surveyed include scratchy throat, cough, hoarseness, phlegm, wheezing, runny or stuffy nose, eye irritation, shortness of breath, and headache. The most commonly reported symptoms for all subjects were phlegm production And runny or stuffy nose. Most positive responses categorized the symptom severity as mild. The prevalence of reported symptoms in children was greater on high ozone days than on low ozone days.

Consistent with previous observations, the current study demonstrated an impact of outdoor ozone levels on peak expiratory flow rates in children. The eight-hour ozone exposure measure showed the strongest relationship between peak flow decrements and ambient ozone levels. Children demonstrated an average loss of between 2.35 and 4.74 ml/sec/ppb. This equates to an average peak flow loss in children of 8.4 percent for each 100 ppb increase in ozone concentration. Thus, childhood peak flow rates appear to provide the most sensitive indicator of ozone response.

No statistically significant relationship was observed for other lung function measures in children. Nor was there a detectable ozone-pulmonary function response relationship for the counselors. One plausible explanation for the lack of statistically significant slopes in this study is the impact of cumulative daily exposures to ambient ozone on the participants. There is evidence from other camp studies that persistent shift in baseline initial ozone episode was larger and much more severe than earlier studies. A major portion of the low individual peak flow rates occurred after the conclusion of the ozone episode. It appears that the presence of an extended ozone episode during the first two weeks of study affected the daily dose-response relationship.

Primary prevention to ozone exposure through decreased ambient levels is the best method for protecting public health. However, it is likely that summer-time ozone levels will remain high for the foreseeable future due to the enormous complexity of the problem. Given this, the only visible public health alternative is to increase the public's awareness (i.e., secondary prevention) of the potential ozone-related health hazards and what can be done on a personal level to reduce those hazards through changing individual behaviors, such as modification of activity levels during ozone episodes.

For the past few years, NJDOH and NJDEP have been actively working together to inform the public about ozone episode, the hazards of ozone exposure and how to reduce overall individual risks. Activities such as the NJDEP Ozone Advisory System (Episode Watch), the NJDOH identification and dissemination of information to high risk groups, and active departmental participation with environmental and educational organizations need to be continued. New Jersey must continue its commitment and efforts to reduce ozone formation as well as to address other significant outdoor air pollution issues that affect public health.



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Last Updated: October 14, 1997