Table 7.

Select epidemiologic studies: lymphoma and exposure to TCE.

Reference	Study population	Exposed cases (no.)	Estimated relative risk (95% CI)
NHL
Cohort studies
Hansen et al. 2001	Male	8	3.5 (1.5–6.9)
	Female	0
	Duration of employment, male
	Unknown	2	3.7 (0.4–13)
	≤ 6.25 years	2	2.5 (0.3–9.2)
	≥ 6.25 years	4	4.2 (1.1–11)
Chang et al. 2005	Male	5	1.3 (0.4–3.0)
	Female	10	1.1 (0.6–2.1)
Raaschou-Nielsen et al. 2003	Male	83	1.2 (1.0–1.5)
	Female	13	1.4 (0.7–2.3)
	Duration of employment, male
	≤ 1 year	23	1.1 (0.7–1.6)
	1–4.9 years	33	1.3 (0.9–1.8)
	≥ 5 years	27	1.4 (0.9–2.0)
	Duration of employment, female
	≤ 1 year	2	0.7 (0.1–2.4)
	1–4.9 years	6	1.6 (0.6–3.5)
	≥ 5 years	5	1.8 (0.6–4.3)
Zhao et al. 2005a	Low TCE score	28	1.0
	Medium TCE score	16	0.9 (0.5–1.7)
	High TCE score	1	0.2 (0.03–1.5)
Community studies
Morgan and Cassady 2002	13 census tracts in San Bernardino County, CA	111	1.1 (0.9–1.3)
Leukemia
Cohort studies
Hansen et al. 2001	Male	5	1.9 (0.6–4.4)
	Female	1	3.1 (0.04–18)
Chang et al. 2005	Male	2	0.4 (0.05–1.6)
	Female	8	0.5 (0.2–1.1)
Raaschou-Nielsen et al. 2003	Male	69	1.1 (0.8–1.4)
	Female	13	1.7 (0.9–2.9)
Community studies
Costas et al. 2002	Exposed to water from TCE-contaminated wells G and H 2 years before pregnancy to leukemia diagnosis
	Never	3	1.0
	Least	9	5.0 (0.7–34)
	Most	7	3.6 (0.5–25)
	Exposed to water from TCE-contaminated wells G and H during pregnancy
	Never	9	1.0
	Least	3	3.5 (0.2–58)
	Most	7	14 (0.9–224)b
Morgan and Cassady 2002	13 census tracts in San Bernardino County, CA	77	1.0 (0.8–1.3)

^aZhao et al. (2005) present both cancer incidence and cancer mortality. Relative risks in this table are for NHL and leukemia incidence combined.

^bTest for trend is statistically significant, p ≤ 0.05.