Table 2.

Births, congenital anomalies, and standardized risk ratios (95% CIs) within 2 km of the landfill sites, 1998–2000.

Sites	Congenital anomalies	Total births	Standardized risk ratio
Before opening and after opening of sites	178	5,297	1.04 (0.88–1.21)
As above but including four sites with significant expansion	204	6,134	1.04 (0.88–1.21)
Fifteen sites introducing containment after opening	124	3,827	1.11 (0.92–1.31)
Eight sites with containment but no gas control	70	2,129	1.19 (0.90–1.48)
Ten sites introducing gas control after opening	55	1,756	1.14 (0.88–1.41)
Three sites with gas control but no containment	1	58	1.03a
Six sites that accept chemical waste	42	1,216	1.08 (0.75–1.41)

^aNumbers are too small to quote reliable CIs.