Question

Everyday exposure to toxic pollutants.

a) Select one specific gas-phase pollutantthat is mentioned in the reading, “Everyday exposure to toxic pollutants”. Briefly summarize (~3-5sentences) Ottand Robert’s findings regarding the pollutant in the article (e.g., we discussed in class that a major source of exposure to the air pollutant benzene was from cigarette smokewhile the predominant emission source by mass is motor vehicle exhaust).

b) For the pollutant you selected, report the compound’s molecular formula, molecular structure, molecular weight, and vapor pressure.The NIST Chemistry Webbook may be of use: https://webbook.nist.gov/chemistry/

c) Search in the peer-reviewed literature (i.e.,google scholar, Web of Science) for an article that reports the concentrationor mixing ratioof your selected pollutant in an indoor environmentof any type (i.e., home, school, office, etc.). Summarize(in a few sentences)the findings of the article toreport i) the type of indoor location in the study, ii) the level of that pollutant reported (this could be a range, average, median etc. depending on the source), and iii) the authors’ motivation for studying this pollutant.

d) Convert the concentration reported in part c) to a mixing ratio(or vice versa if your compound was reported as a mixing ratio)for environmental conditions reported for the indoor environment (or assume reasonable values if not reported).

e) Search for at least one relevant health-based standard for your selected pollutant and compare to the levels found in your selected study. If you cannot identify any standard, report that! (Hint: search for reports from the EPA NAAQS, EPA HAPS (Hazardous air pollutants), OSHA Regulations (Occupational Safety and Health Administration, or Cleaner Air Oregonto identify relevant standards)

Answer 1

a. The gas-phase pollutant disscused here is Benzene.

b. Molecular formula: C₆H₆ , Molecular Weight: 78.1118 g/mol , vapour pressure: 75 torr (at 20^oC)

Molecular Structure:

c. On an average, the dose of benzene in air inhaled by people in one day is:

• Infants: 15-26 ?g; 3.40–5.76 ?g/m3 of benzene is present in air
• Average child: 29-50 ?g; 3.37–5.67 ?g/m3 of benzene is present in air
• Non-occupationally exposed adult: 75-522 ?g; 3.7–41 ?g/m3 of benzene is present in air