Compared to the analysis sample, women who used birth control sporadically and could not report their TTP were more likely to be African American or Asian, slightly more likely to be never married, somewhat better educated, but were similar to the analysis sample for personal income.
Only one person in the study sample paid for personal care out-of-the-pocket.
The filter samples for the personal sampling were collected in the breathing zone using MSA (Escort Elf pump) operated sampling pumps at a flow rate of 1.5 2.0 L/min and SKC (Leland Legacy pump) operated sampling pumps at a flow rate of 6.9 7.3 L/min when the work duration was short.
In discotheques and pubs, where the expected concentration of nicotine was higher and operating hours were mostly at night, we took samples from personal monitors for short periods ranging between 4 and 5 hr.
The percentage of samples above the LOD was greatest for personal samples, with most compounds detected in > 90% of samples.
The improvement of the facial skin was visible and significant when blinded researchers evaluated photos taken initially and after 4 weeks and 8 weeks of treatment, with no visible difference between groups, Figure 4A and B. One of the volunteers dropped out before the first blood sample was taken for personal reasons, whereas the rest of the population, 17 volunteers, completed the study.
Both sampling ways were performed by active air samplers, with Gilian-LFS3 (Sensidyne, Inc., USA) carried by workers for personal sampling and GilAir-5 (Sensidyne, Inc., USA) for stationary sampling.
We similarly split flows for personal sampling into four air streams, with a lower flow to each PEM (1.8 L/min) to allow the use of a single personal pump (BGI 400; BGI Inc., Waltham, MA).
Briefly, for personal sampling, each measurement was recorded as the 8 h time-weighted average (TWA), and, for the subjects' workshift, the average BD measurement for the exposed group (0.34 ± 0.61 p.p.m. or 0.75 ± 1.35 mg/m) was significantly higher (P < 0.01) than that for the control group (0.04 ± 0.01 p.p.m. or 0.09 ± 0.02 mg/m).
