Regional Variation in Human Exposure to Persistent Organic Pollutants in the United States, NHANES

Table 2

Geometric mean and selected percentiles of serum PCBs 138 and 158 and PCB 153 concentrations (in ng/g of lipid or parts per billion on a lipid weight) and HxCDD and HpCDD concentrations (in pg/g of lipid or parts per trillion on a lipid weight basis) for the US population by geographic area, NHANES 2001–2004.

	Ages of 20 years and older
	Geometric mean (95% CI)	Percentile (95% CI)
		50th	90th
2,2′,3,4,4′,5′-Hexachlorobiphenyl and 2,3,3′,4,4′,6-hexachlorobiphenyl (PCBs 138 and 158)
Northeast	27.4 (25.5–29.2)	28.1 (25.7–30.9)	88.7 (77.2–104)
Midwest	19.4 (15.4–23.5)	18.8 (15.3–24.5)	64.7 (50.0–88.4)
South	21.0 (18.2–23.7)	22.5 (19.2–25.3)	69.5 (60.5–76.0)
West	17.3 (15.9–18.6)	16.8 (15.2–19.4)	51.8 (47.5–63.0)
2,2′,4,4′,5,5′-Hexachlorobiphenyl (PCB 153)
Northeast	37.1 (34.2–40.1)	40.5 (36.2–43.7)	118 (95.1–139)
Midwest	26.5 (21.0–32.0)	27.8 (20.4–36.5)	92.4 (66.2–117)
South	28.1 (24.7–31.5)	31.1 (26.7–35.0)	91.3 (78.0–109)
West	24.4 (22.5–26.2)	25.9 (22.3–28.3)	74.3 (68.6–81.3)
1,2,3,6,7,8-Hexachlorodibenzo-p-dioxin (HxCDD)
Northeast	25.1 (18.5–31.6)	29.8 (24.0–37.3)	73.5 (60.6–89.1)
Midwest	29.6 (19.1–40.1)	34.5 (23.3–48.1)	94.2 (53.1–181)
South	25.7 (21.3–30.1)	29.5 (25.4–35.5)	73.4 (62.3–92.4)
West	22.1 (19.1–25.1)	26.0 (22.0–30.6)	60.7 (52.1–74.2)
1,2,3,4,6,7,8-Heptachlorodibenzo-p-dioxin (HpCDD)
Northeast	29.4 (23.2–35.7)	30.1 (24.8–36.5)	82.2 (56.7–115)
Midwest	35.9 (27.7–44.1)	37.1 (27.3–51.0)	112 (75.6–158)
South	34.1 (29.6–38.7)	35.3 (29.6–41.3)	98.2 (83.7–125)
West	27.1 (24.4–29.7)	28.9 (25.9–31.7)	71.7 (66.1–74.7)

Regional means with the same letter superscript are not significantly different from each other based on analysis of covariance adjusting for age, smoking status, gender, and race/ethnicity.