Evaluation of a real-time passive personal particle monitor in fixed site residential indoor and ambient measurements.

Recent experimental findings in animals and humans indicate adverse respiratory effects from short-term exposures to particulate air pollutants, especially in sensitive subpopulations such as asthmatics. The relationship between air pollution and asthma has mainly been determined using particulate matter (PM) measurements from central sites. Validated tools are needed to assess exposures most relevant to health effects. Recently, a personal passive particulate sampler (personal Data-RAM, pDR, MIE Inc., Bedford, MA) has become available for studying personal exposures to PM with time resolution at 1 min. The pDR measures light scatter from PM in the 0.1-10 microM range, the significant range for health effects. In order to assess the ability of the pDR in predicting gravimetric mass, pDRs were collocated with PM2.5 and PM10 Harvard Impactors (HI) inside and outside nine homes of asthmatic children and at an outdoor central Air Pollution Control District site. Results are presented of comparisons between the HI samplers and the pDR in various modes of operation: passive, active, and active with a heated inlet. When used outdoors at fixed sites the pDR readings exhibit interference from high relative humidity (RH) unless operated with a method for drying inlet air such as a heater, or if readings at times of high RH are adjusted. The pDR correlates more highly with the HI PM2.5 than with the HI PM10 (r2 = 0.66 vs. 0.13 for outdoors, r2 = 0.42 vs. 0.20 for indoors). The pDR appears to be a useful tool for an epidemiologic study that aims to examine the relationship between health outcomes and personal exposure to peaks in PM.

Fetal effects of inhalation exposure to cyclohexanone vapor in pregnant rats.

Cyclohexanone (CH), a solvent and thinner that has extensive use in industry, was investigated for developmental effects using pregnant Sprague-Dawley rats exposed to 100, 250 or 500 ppm concentrations in an inhalation chamber for seven hours per day from days 5 through 20 of pregnancy. Controls were exposed to room air. Maternal weight gain at 250 and 500 ppm CH was only slightly lower than in the control dams, and a grey mottling of the lungs was seen in a few of the CH-exposed dams. There were no significant differences between the CH and control groups in fetal weight, resorption sites, fetal death or sex ratio. External and soft tissue examinations revealed no significant incidence of malformations or variations in CH-exposed animals. A slight increase in the mean percent of rudimentary ribs per litter was observed in the 250 and 500 ppm CH-exposed groups. However, no significant numbers of skeletal malformations were noticed in either the CH or room air control groups. It was concluded that respiratory exposure of rats to as much as 500 ppm CH during organogenesis was unlikely to be developmentally toxic.

Occupational exposure to asbestos fibers resulting from use of asbestos gloves.

To assess the magnitude of fiber emission from asbestos gloves, 10 pairs were compared in an isolation chamber during simulation of a sterilization procedure; 176 air samples were collected. Means of time weighted average (TWA) concentrations ranged from 0.95 to 11.74 fibers (greater than 5 micrometers)/cm3 of air. Well-worn/clean gloves emitted significantly more fibers than did brand-new gloves, but fiber emission decreased with increased surface soiling. Eighty air samples were collected during simulation of the sterilization procedure in a well-ventilated room. The range of mean TWA concentrations was 0.07-0.99 fiber/cm3 for breathing zone samples and 0.06 to 0.60 fiber/cm3 for area samples. Thirteen samples were collected at actual workplaces; the range of TWA concentrations was 0.07-2.93 fibers/cm3 for breathing zone samples and 0.04-0.74 fiber/cm3 for area samples. Five of seven breathing zone samples from workplaces exceeded the proposed TWA concentration limit of 0.1 asbestos fiber/cm3. Hand contamination also was assessed. Four samples collected after touching the worktable ranged from 9953 to 13 108 fibers (greater than 5 micrometers)/cm2 of hand surface area; seven samples collected immediately after taking off gloves ranged from 741 to 3860 fibers/cm2. Available substitutes for asbestos gloves are discussed, and adoption of these substitutes is recommended strongly.