Document Type

Capstone Experience

Graduation Date

12-2019

Degree Name

Master of Public Health

Department

Environmental, Agricultural & Occupational Health

First Committee Member

Dr. Chandran Achutan

Second Committee Member

Dr. Karen Bradham

Third Committee Member

Dr. Christopher Wichman

Abstract

Lead-dust monitoring studies report values as either lead-dust loadings µg/ft2 or as lead-dust concentrations µg/g. It is rare for studies to report both metrics. When only lead-dust loading values are present, professionals require an approach to estimate lead-dust concentration values. A literature search identified five studies that contained raw data for both lead-dust loading and lead-dust concentration. An additional thirty-two studies had summary-statistics available for both lead-dust loading and lead-dust concentration. Studies with raw-data were used to develop an empirically-based loading to concentration statistical relationship. Raw data sets were critically evaluated to determine whether elimination or substitution of data points was warranted. Studies with summary statistics were used to evaluate this relationship using independent data. Despite the differences in study-design, sampling method, and analytical procedures, the overall empirical relationship across studies with raw data remained consistent. The r2 value between lead-dust loading and lead-dust concentration improved from 0.30 to 0.55 for raw data sets to 0.55 to 0.58 for pooled data sets. The standard error of the regression, slope, and intercept were also improved. Reported central-tendency summary statistics from independent data sets showed that measured central tendency dust lead concentrations from these studies were similar to predicted dust lead concentrations using the regression derived from raw data sets. Across 142 extracted paired lead-dust loading and lead-dust concentration pairs from independent data, >90% of estimated lead-dust concentration values were within an 80% prediction interval. The loading to concentration relationship developed from this data is log-log linear. The most likely reason is due to variable total dust loadings (g/ft2), which result in one lead-dust loading value being linked to a range of lead-dust concentration values. When only lead-dust loading values are present, this empirical relationship provides a reasonable approach to estimate lead-dust concentrations.

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