Hourly Measurements of Fine Particulate Sulfate and Carbon Aerosols at the Harvard–U.S. Environmental Protection Agency Supersite in Boston

Abstract

Hourly concentrations of ambient fine particle sulfate and carbonaceous aerosols (elemental carbon [EC], organic carbon [OC], and black carbon [BC]) were measured at the Harvard–U.S. Environmental Protection Agency Supersite in Boston, MA, between January 2007 and October 2008. These hourly concentrations were compared with those made using integrated filter-based measurements over 6-day or 24-hr periods. For sulfate, the two measurement methods showed good agreement. Semicontinuous measurements of EC and OC also agreed (but not as well as for sulfate) with those obtained using 24-hr integrated filter-based and optical BC reference methods. During the study period, 24-hr PM2.5 (particulate matter [PM] ≤ 2.5 μm in aerodynamic diameter) concentrations ranged from 1.4 to 37.6 μg/m3, with an average of 9.3 μg/m3. Sulfate as the equivalent of ammonium sulfate accounted for 39.1% of the PM2.5 mass, whereas EC and OC accounted for 4.2 and 35.2%, respectively. Hourly sulfate concentrations showed no distinct diurnal pattern, whereas hourly EC and BC concentrations peaked during the morning rush hour between 7:00 and 9:00 a.m. OC concentrations also exhibited nonpronounced, small peaks during the day, most likely related to traffic, secondary organic aerosol, and local sources, respectively.

Contributions of vehicular carbonaceous aerosols to PM<sub>2.5</sub> in a roadside environment in Hong Kong

“…The average dynamic blank corresponds to 8.7 % of the measured annual mean OC value. This value is consistent with the results from previous studies (e.g., Polidori et al, 2006;Kang et al, 2010) and the finding from Turpin et al (1994) that the adsorption artifact is dependent on the concentrations of gaseous OC/particulate OC. The volatilization of particulate OC from the sampling quartz fiber filter was estimated to be 10 ± 6 % (upper limit) (Polidori et al, 2006).…”

Short‐Term Exposure to Air Pollution and Biomarkers of Oxidative Stress: The Framingham Heart Study

“…The study participants were from the Framingham Heart Study Offspring cohort living within 50 km of the Harvard Supersite air pollution monitor in Boston, Massachusetts 31. The study design and selection criteria of the Framingham Offspring cohort has been described elsewhere 32.…”

“…Measurement methods have been described previously 31. PM 2.5 (μg/m 3 ) was measured by using a tapered element oscillating microbalance (Model 1400A; Rupprecht & Patashnick Co Inc), and BC (μg/m 3 ) was measured by using an aethalometer (Model AE‐16; Magee Scientific Corp).…”

Reprint of: Perinatal and early childhood environmental factors influencing allergic asthma immunopathogenesis

“…Fine particles affect respiratory symptoms in children with asthma [110,111]. Ambient PM 2.5 tends to be regionally distributed, however, the black carbon component (7-10%) [112] is a particularly sensitive marker for local traffic related pollution [113] and has more spatial variability in the urban setting [114,115]. Large epidemiologic studies have tied the concentration of traffic related air pollution, largely PM 2.5 , with asthma, hay fever and sensitization to pollen [116,117].…”