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Exposure to Elemental Carbon, Organic Carbon, Nitrate, and Sulfate Fractions of Fine Particulate Matter and Risk of Preterm Birth in New Jersey, Ohio, and Pennsylvania (2000-2005).

Rappazzo KM, Daniels JL, Messer LC, Poole C, Lobdell DT - Environ. Health Perspect. (2015)

Bottom Line: We estimated risk differences (RD) of PTB (reported per 106 pregnancies) associated with change in ambient concentrations of elemental carbon (EC), organic carbon (OC), nitrates (NO3), and sulfates (SO4).EC was positively associated with PTB after 27 and before 35 weeks of gestation.We observed effect measure modification for associations between EC and PTB by race/ethnicity and smoking status.

View Article: PubMed Central - PubMed

Affiliation: Department of Epidemiology, UNC Gillings School of Global Public Health, Chapel Hill, North Carolina, USA.

ABSTRACT

Background: Particulate matter ≤ 2.5 μm in aerodynamic diameter (PM2.5) has been consistently associated with preterm birth (PTB) to varying degrees, but roles of PM2.5 species have been less studied.

Objective: We estimated risk differences (RD) of PTB (reported per 106 pregnancies) associated with change in ambient concentrations of elemental carbon (EC), organic carbon (OC), nitrates (NO3), and sulfates (SO4).

Methods: From live birth certificates from three states, we constructed a cohort of singleton pregnancies at or beyond 20 weeks of gestation from 2000 through 2005 (n = 1,771,225; 8% PTB). We estimated mean species exposures for each week of gestation from monitor-corrected Community Multi-Scale Air Quality modeling data. RDs and 95% confidence intervals (CIs) for four PTB categories were estimated for each exposure using linear regression, adjusted for maternal race/ethnicity, marital status, education, age, smoking, maximum temperature, ozone, and season of conception. We also adjusted for other species in multi-species models.

Results: RDs varied by exposure window and outcome period. EC was positively associated with PTB after 27 and before 35 weeks of gestation. For example, for a 0.25-μg/m(3) increase in EC exposure during gestational week 9, RD = 96 (95% CI: -20, 213) and RD = 145 (95% CI: -50, 341) for PTB during weeks 28-31 and 32-34, respectively. Associations with OCs were or negative. RDs for NO3 were elevated with exposure in early weeks of gestation, and in later weeks. RDs for SO4 exposure were positively associated with PTB, though magnitude varied across gestational weeks. We observed effect measure modification for associations between EC and PTB by race/ethnicity and smoking status.

Conclusion: EC and SO4 may contribute to associations between PM2.5 and PTB. Associations varied according to the timing of exposure and the timing of PTB.

No MeSH data available.


Related in: MedlinePlus

Risk differences per 1,000,000 pregnancies for 0.25-μg/m3 increases in EC. Single-species models were adjusted for maternal education, race/ethnicity, marital status, age at delivery, smoking, season of conception, maximum temperature, and O3. Multi-species models are also adjusted for OC, NO3, and SO4. (A) ExPTB: birth at 20–27 weeks, (B) VPTB: birth at 28–31 weeks, (C) MPTB: birth at 32–34 weeks, and (D) LPTB: birth at 35–36 weeks of gestation.
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f1: Risk differences per 1,000,000 pregnancies for 0.25-μg/m3 increases in EC. Single-species models were adjusted for maternal education, race/ethnicity, marital status, age at delivery, smoking, season of conception, maximum temperature, and O3. Multi-species models are also adjusted for OC, NO3, and SO4. (A) ExPTB: birth at 20–27 weeks, (B) VPTB: birth at 28–31 weeks, (C) MPTB: birth at 32–34 weeks, and (D) LPTB: birth at 35–36 weeks of gestation.

Mentions: PTB RDs associated with a 0.25-μg/m3 increase in EC, with exposure at each week of gestation, are shown in Figure 1. For EC exposure, ExPTB RDs were for exposure at all gestational weeks, with similar estimates from single- and multi-species models. For VPTB, single-species model RDs were slightly elevated at some points in mid-pregnancy, though many weeks were near . However, EC RDs were generally higher in multi-species models. For MPTB, single-species RDs were elevated with exposure to EC at gestational weeks 4 and 5, and consistently positive from week 7 through week 21. Multi-species model RDs were positive for exposures in weeks 1–21, and higher than corresponding RDs from the single-species models. For LPTB, RDs from single-species models were consistently negative or , whereas EC RDs from multi-species models were positive for exposures during weeks 1–24.


Exposure to Elemental Carbon, Organic Carbon, Nitrate, and Sulfate Fractions of Fine Particulate Matter and Risk of Preterm Birth in New Jersey, Ohio, and Pennsylvania (2000-2005).

Rappazzo KM, Daniels JL, Messer LC, Poole C, Lobdell DT - Environ. Health Perspect. (2015)

Risk differences per 1,000,000 pregnancies for 0.25-μg/m3 increases in EC. Single-species models were adjusted for maternal education, race/ethnicity, marital status, age at delivery, smoking, season of conception, maximum temperature, and O3. Multi-species models are also adjusted for OC, NO3, and SO4. (A) ExPTB: birth at 20–27 weeks, (B) VPTB: birth at 28–31 weeks, (C) MPTB: birth at 32–34 weeks, and (D) LPTB: birth at 35–36 weeks of gestation.
© Copyright Policy - public-domain
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4590756&req=5

f1: Risk differences per 1,000,000 pregnancies for 0.25-μg/m3 increases in EC. Single-species models were adjusted for maternal education, race/ethnicity, marital status, age at delivery, smoking, season of conception, maximum temperature, and O3. Multi-species models are also adjusted for OC, NO3, and SO4. (A) ExPTB: birth at 20–27 weeks, (B) VPTB: birth at 28–31 weeks, (C) MPTB: birth at 32–34 weeks, and (D) LPTB: birth at 35–36 weeks of gestation.
Mentions: PTB RDs associated with a 0.25-μg/m3 increase in EC, with exposure at each week of gestation, are shown in Figure 1. For EC exposure, ExPTB RDs were for exposure at all gestational weeks, with similar estimates from single- and multi-species models. For VPTB, single-species model RDs were slightly elevated at some points in mid-pregnancy, though many weeks were near . However, EC RDs were generally higher in multi-species models. For MPTB, single-species RDs were elevated with exposure to EC at gestational weeks 4 and 5, and consistently positive from week 7 through week 21. Multi-species model RDs were positive for exposures in weeks 1–21, and higher than corresponding RDs from the single-species models. For LPTB, RDs from single-species models were consistently negative or , whereas EC RDs from multi-species models were positive for exposures during weeks 1–24.

Bottom Line: We estimated risk differences (RD) of PTB (reported per 106 pregnancies) associated with change in ambient concentrations of elemental carbon (EC), organic carbon (OC), nitrates (NO3), and sulfates (SO4).EC was positively associated with PTB after 27 and before 35 weeks of gestation.We observed effect measure modification for associations between EC and PTB by race/ethnicity and smoking status.

View Article: PubMed Central - PubMed

Affiliation: Department of Epidemiology, UNC Gillings School of Global Public Health, Chapel Hill, North Carolina, USA.

ABSTRACT

Background: Particulate matter ≤ 2.5 μm in aerodynamic diameter (PM2.5) has been consistently associated with preterm birth (PTB) to varying degrees, but roles of PM2.5 species have been less studied.

Objective: We estimated risk differences (RD) of PTB (reported per 106 pregnancies) associated with change in ambient concentrations of elemental carbon (EC), organic carbon (OC), nitrates (NO3), and sulfates (SO4).

Methods: From live birth certificates from three states, we constructed a cohort of singleton pregnancies at or beyond 20 weeks of gestation from 2000 through 2005 (n = 1,771,225; 8% PTB). We estimated mean species exposures for each week of gestation from monitor-corrected Community Multi-Scale Air Quality modeling data. RDs and 95% confidence intervals (CIs) for four PTB categories were estimated for each exposure using linear regression, adjusted for maternal race/ethnicity, marital status, education, age, smoking, maximum temperature, ozone, and season of conception. We also adjusted for other species in multi-species models.

Results: RDs varied by exposure window and outcome period. EC was positively associated with PTB after 27 and before 35 weeks of gestation. For example, for a 0.25-μg/m(3) increase in EC exposure during gestational week 9, RD = 96 (95% CI: -20, 213) and RD = 145 (95% CI: -50, 341) for PTB during weeks 28-31 and 32-34, respectively. Associations with OCs were or negative. RDs for NO3 were elevated with exposure in early weeks of gestation, and in later weeks. RDs for SO4 exposure were positively associated with PTB, though magnitude varied across gestational weeks. We observed effect measure modification for associations between EC and PTB by race/ethnicity and smoking status.

Conclusion: EC and SO4 may contribute to associations between PM2.5 and PTB. Associations varied according to the timing of exposure and the timing of PTB.

No MeSH data available.


Related in: MedlinePlus