CAROLYN WHITAKER
Accuracy of Construction Worker Recall of Tasks for Epidemiological Exposure Assessment to Noise
Industrial Hygiene and Safety, MS
Preceptor: Noah Seixas, PhD
Accurate recall of tasks is key to estimating noise exposure in epidemiological studies using task-based methods. In order to evaluate worker recall, information reported on a daily activity card was compared with the same information recalled at interview six months later. A cohort of 25 construction workers (predominantly electricians and carpenters) recorded tasks daily and had dosimetry measurements weekly for a six-week period. Exposure levels (LAvg) were calculated for each task. To evaluate worker recall, the average percent time in each task was calculated from the activity cards and compared to percentages recalled during the interview. To estimate actual noise exposure, the average decibel level for each task was multiplied by the percent time reported on either the task card or the interview and summed over all tasks done in a day.
The mean noise exposure level (dBA) from dosimeter measurements was 83.1 ? 3.9 (n=61) and 76.7 ? 5.5 (n=47) for carpenters and electricians, respectively. The percent time at tasks reported during the interview was compared to that calculated from daily activity cards; only two out of 22 tasks were significantly different (p < 0.05). The median accuracy (bias and precision) of percent time at tasks from the interview was 91%. Task-based estimates of exposure for carpenters were 84.7 ? 0.7 dBA and 85.1 ? 0.5 dBA using interviews and task cards, respectively. The comparable numbers for electricians were 79.8 ? 1.7 dBA and 79.1 ? 0.5 dBA, respectively, and none of these differences were statistically significant (p > 0.05).
In conclusion, six months after tasks were performed, construction workers were able to accurately recall the percent time they spent at various tasks. The exposure levels estimated using recalled task information were sufficiently accurate for epidemiological exposure assessment.
