Epidemiologic investigations of building-related health complaints document that volatile organic compounds (VOCs), stressors, and individual characteristics (e.g., female gender) contribute to the reported non-specific symptoms. The purpose of the proposed study was to determine the effects of a psychological stressor and the individual difference variables, negative affect and odor intolerance, on responses of women to a mixture of volatile organic compounds with and without ozone. One hundred and thirty healthy women (mean age = 27.2 year's; mean education = 15 years) participated in a 2 (Negative Affect -high & low) x 2 (Odor Intolerance -high & low) x 2 (Stressor) x 3 (Exposures: masked clean air (MCA), VOCs, VOCs with" ozone (VOC + O) repeated measures design. All subjects completed each exposure condition. One-half of the subjects were randomly assigned to exposure conditions with the stressor while file remaining subjects completed the exposures without the stressor. During each 3 hour exposure condition, health effects measured before, during and after exposure included: symptom questionnaires, neurobehavioral performance, salivary cortical, nasal inflammation (PMN, albumin, IL-6- IL-8), and lung function (FEY 1 ). Secondary stable products of the ozone-VOC reaction were measured during the VOCs + O sessions only. Among healthy women, exposure to concentrations of VOCs with and without ozone did not result in significant subjective or objective health effects. Combining VOCs with ozone at a low ventilation rate (approximately 2 air exchanges per hour) was successful in producing aldehydes, organic acids and submicron particles primarily through the interaction of ozone with terpenes (283 ppb ). Despite the addition of these potentially irritating products, subjects' ratings of health symptoms, environmental qualities, and odor were indistinguishable between the VOCs + O and the VOCs condition. Although numerous epidemiologic studies suggest that symptoms are significantly increased among workers in buildings with poor ventilation and mixtures of VOCs (e.g., Mendell et al., 2002; Mendell, 1993; Sieber et al., 1996), the current controlled acute exposure: to similar chemical mixtures did not validate these epidemiologic findings. Similar to previous studies, however, subjects in the present study found the air quality and odor to be poorer in the VOCs and VOCs + O than in the MCA condition. Even though the MCA condition was intentionally "spiked" with the odor of the VOC mixture, subjects perceived this odor to be of lesser strength and the air of better quality than for the VOCs and VOCs + O conditions. Although symptoms were not significantly increased, subjects rated the VOCs and VOCs + O conditions as more annoying if these conditions were present in their daily work environment. Psychological stress, on the other hand, significantly increased salivary cortisol for all subjects and ratings of anxiety particularly' among women high in negative affect. In fact, psychological stress overwhelmed any effect of exposure on symptoms of anxiety for subjects high in negative affect. In contrast, subjects low in negative affect reported greater anxiety following the psychological stressor and during the VOCs + O condition. However, the addition of psychological stress did not exacerbate other health symptoms for any subject group. Objective markers including lung function, nasal inflammation, and neurobehavioral performance were also not affected by exposure to VOCs with or without ozone. Contrary to the hypothesis, subjects high in chemical intolerance did not report more symptoms or show elevation on markers of nasal inflammation in response to VOCs with ozone. In conclusion, the present study suggests that indoor air complaints may be driven by annoyance with unpleasant odors. The effects of psychological stress may be operating independently to increase symptoms of anxiety particularly among individuals who are prone to negative affect. These symptoms may be mistakenly attributed to poor indoor air quality.
University of Medicine and Dentistry of New Jersey - Robert Wood Johnson Medical School, Environmental and Occupational Health Sciences Institute, 170 Frelinghuysen Road, Room 210, Piscataway, NJ 08854