Table 3.
Estimated per-capita release rates of organohalogens to wastewater, and computed rates of annual chemical release to wastewater and soils nationwide.
| Compound | Per-capita Loading Mean ± 95%CI (mg/year) |
Nationwide Loading to Wastewater Rate ± 95%CI (kg/year) |
Nationwide Land Application Rate ± 95%CI (kg/year)a,b |
Nationwide Release with Treated Wastewater Rate ± 95%CI (kg/year)b |
|---|---|---|---|---|
| 4,4’-Dichloro- carbanilide |
30 ± 20 (n = 11) |
9,500 ± 6,500 (n = 11) |
16,700 ± 14.300 (n = 6) |
5,900 ± 3,600 (n = 10) |
| Dichlorophene | N/A | N/A | 850 ± 900 (n = 6) |
N/A |
| Fipronil | 6 ± 1 (n = 11) |
1,700 ± 400 (n = 11) |
440 ± 390 (n = 6) |
1,500 ± 400 (n = 10) |
| Hexachlorophene | N/A | N/A | 5,300 ± 4,200 (n = 6) |
N/A |
| 3,3’,4,4’- Tetrachlorocarbanilide |
N/A | N/A | 8,400 ± 2,800 (n = 6) |
N/A |
| Triclocarban | 950 ± 250 (n = 49) |
275,000 ± 66,000 (n = 49) |
132,000 ± 36,000 (n = 10) |
11,000 ± 4,000 (n = 13) |
| Triclosan | 1,100 ± 280 (n = 49) |
326,000 ± 81,000 (n = 49) |
64,000 ± 29,000 (n = 10) |
16,000 ± 14,000 (n = 13) |
a
Assuming 63% sludge recycling rate for application of biosolids on land (3).
b
Only activated sludge wastewater treatment plants using anaerobic digestion were included, as this represents the most prevalent treatment strategy in the U.S. based on sewage volume treated.