Abstract submitted to: AAAR International specialty conference: "Air Pollution 

and Health: Bridging the Gap from Sources to Health Outcomes." 11/09/09

Children’s exposure to airborne PM2.5 and manganese near a ferromanganese refinery 

in Southeast Ohio

M. Terrell,1 T. Reponen,1 D. Brown,2 P. Ryan,1 E. Haynes1

1University of Cincinnati, Department of Environmental Health, Cincinnati, OH

2Marietta College, Department of Biology and Environmental Sciences, Marietta, OH

Occupational studies have shown that excess exposure to Mn can cause neurotoxic 

effects though little is known regarding health effects of ambient Mn exposure in children. 

A ferromanganese refinery in Marietta, OH reports the greatest amount of Mn fugitive air 

emissions in the nation. The aim of this study was to compare ambient levels of Mn in 

Marietta with those in a control city (Cambridge, OH) and to compare personal air 

monitoring results with the results obtained at stationary outdoor sites in Marietta. This 

study is part of a larger epidemiological study on the neurotoxic effects of Mn exposure 

in children, the Communities Actively Researching Exposure Study (CARES).

Stationary outdoor air samples were collected at two locations: Marietta College and 

Robinson Hill Rd, 5 and 2 miles from the refinery, respectively. The sampling was 

conducted for 8 months at Marietta College (n=83) and during three weeks at the 

Robinson Hill station (n=8). In Cambridge, 43 miles north of Marietta, stationary 

sampling was conducted for one week per season (n=10). Stationary samples were 

collected on Teflon filters for approximately 48 hours using Harvard-type PM2.5 

impactors (MS&T Area Sampler; Air Diagnostics, Inc.). Personal air samples were 

collected on 20 participants, ages 7-9, living in non-smoking households enrolled in 

CARES. The personal sampling was conducted for 48 hours using PM2.5 samplers 

(Personal Modular Impactor; SKC Inc). Time weighted average (TWA) distance was 

computed to determine how far the personal sample was from the Mn refinery, based on 

reported activities. All air samples were analyzed for PM2.5 mass gravimetrically and for 

Mn, Al, Cr and Pb using inductively coupled plasma mass spectrometer. Al was selected 

as a crustal indicator element. Cr and Pb were selected because these elements are 

emitted from the refinery and other facilities in Marietta.

The PM2.5 mass measured at the three stationary sites varied from 0.07 to 27.5 

micrograms/cubic meter and was not significantly different between the three sites. In 

contrast, Mn concentrations increased when the distance to the refinery decreased. The 

geometric mean concentrations (GM) for Cambridge, Marietta College and Robinson Hill 

were 2.0, 6.7, and 46.1 nanograms/cubic meter, respectively (ANOVA: p < 0.001). A 

similar trend was seen for Al, Cr and Pb, but the differences were not statistically 

significant.

Personal samples had higher GM for PM2.5 and for the four metals than respective 

stationary samples. The largest differences between personal and outdoor stationary 

results were found with the crustal indicator Al, which was 4.2 times higher in personal 

than in stationary samples (p=0.03) and with the PM2.5 mass (2.9 times higher; p=0.01). 

Log-transformed TWA distance was significantly associated with log-transformed 

personal Mn (p=.04) and personal Pb (p=0.01) and explained approximately 21% and 

29% of the variability in personal exposure to Mn and Pb, respectively. The results 

indicate that children’s PM2.5 exposure in Marietta is uniform throughout the city. Mn 

exposure is associated with the child’s residential and school distance to the refinery.