Research Association between Trafﬁc-Related Black Carbon Exposure and Lung Function among Urban Women Shakira Franco Suglia,1 Alexandros Gryparis,2 Joel Schwartz,1,3 and Rosalind J. Wright 1,3 1Department of Environmental Health, Harvard School of Public Health, Boston, Massachusetts, USA; 2Department of Hygiene and Epidemiology, University of Athens, Athens, Greece; 3Channing Laboratory, Brigham and Women’s Hospital, Boston, Massachusetts, USA BACKGROUND: Although a number of studies have documented the relationship between lung func- tion and trafﬁc-related pollution among children, few have focused on adult lung function or exam- ined community-based populations. OBJECTIVE: We examined the relationship between black carbon (BC), a surrogate of trafﬁc-related particles, and lung function among women in the Maternal–Infant Smoking Study of East Boston, an urban cohort in Boston, Massachusetts. METHODS: We estimated local BC levels using a validated spatiotemporal land-use regression model, derived using ambient and indoor monitor data. We examined associations between percent predicted pulmonary function and predicted BC using linear regression, adjusting for sociodemo- graphics (individual and neighborhood levels), smoking status, occupational exposure, type of cook- ing fuel, and a diagnosis of asthma or chronic bronchitis. RESULTS: The sample of 272 women 18–42 years of age included 57% who self-identified as Hispanic versus 43% white, and 18% who were current smokers. Mean ± SD predicted annual BC exposure level was 0.62 ± 0.2 µg/m3. In adjusted analysis, BC (per interquartile range increase) was associated with a 1.1% decrease [95% conﬁdence interval (CI), –2.5% to 0.3%] in forced expira- tory volume in 1 sec, a 0.6% decrease (95% CI, –1.9% to 0.6%) in forced vital capacity, and a 3.0% decrease (95% CI, –5.8% to –0.2%) in forced mid-expiratory ﬂow rate. We noted differential effects by smoking status in that former smokers were most affected by BC exposure, whereas cur- rent smokers were not affected. CONCLUSION: In this cohort, exposure to traffic-related BC, a component of particulate matter, independently predicted decreased lung function in urban women, when adjusting for tobacco smoke, asthma diagnosis, and socioeconomic status. KEY WORDS: air pollution, lung function, particles, trafﬁc. Environ Health Perspect 116:1333–1337 (2008). doi:10.1289/ehp.11223 available via http://dx.doi.org/ [Online 4 June 2008] It is well documented that air pollution is associated with a number of respiratory and cardiovascular adverse health effects (Beelen et al. 2008; Downs et al. 2007; Katsouyanni et al. 1997; Schwartz 1996; Schwartz et al. 2005). Many of these effects seem more strongly associated with particles from trafﬁc (McCreanor et al. 2007; Schwartz et al. 2005), which are rich in elemental carbon and are the principle source of ultraﬁne particle exposure. Concentrations of traffic-related pollutants [i.e., particulate matter (PM), black carbon (BC), nitrogen dioxide] have been found to increase respiratory symptoms among children (Kim et al. 2004). Among children, long-term exposure to air pollution (Schwartz 1989, 2004) and indicators of increased trafﬁc expo- sure (Brunekreef et al. 1997; Gauderman et al. 2007; Wjst et al. 1993) have been associated with reduced levels of lung function, a more objective measure of respiratory health. A few studies have examined the relation- ship between lung function and long-term exposure to traffic pollution among adults. Among those that have, reduced lung function has been demonstrated among adults with increased trafﬁc exposure (Evans et al. 1988; Kan et al. 2007; Karita et al. 2001; Schikowski et al. 2005; Sekine et al. 2004), although some studies have found no association (Nakai et al. 1999; Tollerud et al. 1983). Furthermore, these studies have focused largely on occupa- tional populations (Evans et al. 1988; Karita et al. 2001; Raaschou-Nielsen et al. 1995; Tollerud et al. 1983), whereas data on com- munity-based populations remain sparse (Kan et al. 2007; Schikowski et al. 2005; Sekine et al. 2004). In a community-based study of women 30–59 years of age in Tokyo, Japan, Sekine et al. (2004) reported decreased lung function among women living in districts with high traffic density (> 20,000 vehicles) compared with women living in districts with lower average trafﬁc density. A recent community- based study in four communities in the United States demonstrated decreased lung function among middle-age women related to increased trafﬁc density and closer proximity to major roadways (Kan et al. 2007). We expand this work by examining BC from mobile sources estimated using a validated spatiotemporal land-use regression model as a surrogate of trafﬁc particles. BC from trafﬁc sources has been associated with increased risk of asthma and bronchitis among children (Kim et al. 2004), and elemental carbon has been associated with decreased growth in lung function, also among children (Gauderman et al. 2004). Environmental Health Perspectives • VOLUME 116 | NUMBER 10 | October 2008 Our goal in this study was to examine the relationship between long-term exposure to BC from trafﬁc sources, a component of PM, and lung function among women of childbearing age followed in a prospective urban commu- nity-based cohort study of mother–child pairs. Materials and Methods Study population. Women were voluntary participants in the Maternal–Infant Smoking Study of East Boston, a prospective cohort originally designed to study the effects of pre- and postnatal tobacco smoke exposure on childhood lung growth and development and respiratory health. The study has been described in detail previously (Hanrahan et al. 1992). In brief, pregnant women receiv- ing prenatal care (< 20th week of gestation) at an urban community health center in Boston, Massachusetts, were recruited during the study’s enrollment period, between March 1986 and October 1992. A total of 848 women delivered a full-term infant and remained eligible for postnatal follow-up. A random sample of women was approached for lung function testing; 272 women com- pleted the test and had their home addresses successfully geocoded. There were no signiﬁ- cant differences between those who partici- pated in the lung function assessment and those who did not, based on sociodemo- graphics, asthma diagnosis, or tobacco smoke exposure. All participants gave voluntary writ- ten consent at the start of the study. The study was approved by the human studies committees at the Harvard School of Public Health, Brigham and Women’s Hospital, and the Beth Israel Deaconess Medical Center. We estimated exposure to BC based on residence assessed at the time of enrollment, which occurred between 1986 and 1992. To predict residential BC level, we developed a validated spatiotemporal land-use regression Address correspondence to S. Franco Suglia, Harvard School of Public Health, Department of Environmental Health, Landmark 415W, 401 Park Dr., Boston, MA 02215 USA. Telephone: (617) 943-7623. Fax: (617) 384-8859. E-mail: sfranco@ hsph.harvard.edu This work was supported by U.S. Environmental Protection Agency grants R827353 and R832416 and National Institutes of Health grants ES015172- 01, ES-00002, T32 ES007142, T32 MH073122, and K08 HL 04187. The authors declare they have no competing ﬁnancial interests. Received 1 January 2008; accepted 3 June 2008. 1333