Scenario 2 - Happy Birthday, Tracy: An industrial hygienist is considering eliminating unfavorable exposure results due to sampling irregularities that may or may not have occurred Case Summary Tracy is an industrial hygienist at a struggling U.S. specialty steel making facility. Some union workers are concerned about exposure to zinc oxide and lead in the workplace (apparently a sister plant in Canada had issues in these areas recently), even though past sampling events at the facility have shown that worker exposures have always been less than the 8-hr TWA PEL's for zinc oxide (15 mg/m3 for total dust; 5 mg/m3 for respirable fraction) and lead (50 µg/m3). Tracy knows that the processes have not been optimal in terms of stability for the last month or so. Tracy equally understands that management does not want to worry about imposing any additional controls since monies are tight, unless there is a true, documented, and substantial problem. So, Tracy is asked by management and the union to collect samples for analyses. Tracy conducts a round of sampling (one sample taken daily during a week for each constituent of concern at a single location historically associated with the highest readings of dusts, vapors and gases). Tracy also knows that as the week progresses, the processes are becoming more unstable, like the previous four weeks' trend. On Friday, since Tracy wants to leave as soon as possible to make a family event that evening (e.g., a "surprise" 40th birthday party for Tracy), Tracy sort of "rushes" the sampling. Tracy is a bit excited in anticipation of a great evening and is unfocused on the work being performed. But Tracy is pretty sure everything has been conducted in a "copasetic" manner (Tracy has been doing this for 15 years.). Tracy sends the samples off for analyses, and these are the results that are received: 8-hr TWA 8-hr TWA Zinc Oxide (total dust), mg/m³ MONDAY 3 TUESDAY 3 WEDNESDAY 4 THURSDAY 8 FRIDAY 18* Zinc Oxide (respirable fraction), mg/m³ 8-hr TWA Lead, µg/m³ 1 1 1 3 10 13 14 20 60* Zinc Oxide 8-hr TWA PEL: 15 mg/m3 for total dust, 5 mg/m3 for respirable fraction Lead 50 µg/m3 * exceeds PEL Dilemma Hmmm. Those Friday results look suspect to Tracy. It would make life so much easier for Tracy just to eliminate Friday's results and chalk it up to sampling error due to pre-Birthday Party exuberance. Tracy contemplates not reporting the Friday results and issuing a report indicating that the analysis

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