7942

• UCREFRP Catalog Number: 7942
• Author: Schmitt, C. J., et al.
• Title: National Pesticide Monitoring Program
• USFW Year: 1983.
• USFW - Doc Type: Organochlorine Residues in Freshwater Fish, 1976-79.
• Copyright Material: NO

18
Table 8. Ranking of NPMP stations in order of decreasing geometric mean concentrations of residues of selected compounds
for the collection periods 1976-77 and 1978-79. See Fig. 1 for locations of stations.
1976-77 1978-79 1976-77 1978-79 1976-77 1978-79
Station Station Station Station Station Station
Rank No. Mean No. Mean No. Mean No. Mean No. Mean No. Mean
p,p'-DDE p,p'- DDT EDDTa
1 104 2.94 80 5.02 104 1.12 80 0.80 80 4.70 80 7.64
2 80 2.42 16 2.31 80 0.92 14 0.52 104 4.47 16 2.58
3 21 1.93 28 1.49 21 0.50 115 0.39 21 2.66 105 1.97
4 16 1.67 105 1.35 115 0.42 100 0.17 16 1.78 28 1.88
5 105 1.20 4 1.31 14 0.29 99 0.17 105 1.56 14 1.72
6 107 1.01 14 1.14 22 0.22 81 0.16 14 1.42 4 1.65
7 14 0.93 21 1.05 105 0.19 105 0.15 107 1.38 71 1.63
8 4 0.89 104 0.90 9 0.18 104 0.15 4 1.16 21 1.48
9 9 0.73 71 0.85 55 0.17 30 0.14 115 1.09 115 1.38
10 48 0.70 115 0.83 33 0.15 21 0.14 44 0.96 104 1.24
Median - 0.16 - 0.15 - 0.01 - 0.02 - 0.20 - 0.24
----- ------ ------------
EPCBb ----- ------ -----------
Toxaphene ------ ------ -----
Diel ------
drinc -----
1 3 33.9 3 44.1 80 8.73 80 12.97 100 1.22 100 1.48
2 69 6.0 2 11.0 104 7.21 105 4.33 90 0.94 105 0.57
3 54 5.2 24 6.4 21 4.96 102 4.25 105 0.49 104 0.42
4 107 5.1 69 5.9 22 3.52 104 3.86 104 0.39 21 0.35
5 21 5.0 54 5.3 105 2.91 21 3.62 21 0.31 83 0.30
6 2 5.0 107 4.8 102 2.90 83 1.92 73 0.24 31 0.20
7 111 4.5 105 4.7 76 2.82 81 1.73 26 0.22 26 0.18
8 105 4.3 23 4.4 103 2.12 71 1.63 68 0.16 75 0.18
9 18 4.2 20 3.4 14 2.04 59 1.44 15 0.14 68 0.15
10 24 3.9 21 3.2 9 1.79 30 1.35 69 0.12 89 0.14
Median - 0.5 - 0.5 - <0.01 - 0.13 - 0.01 - 0.02
aSum of p,p'-homologs.
bAroclors 1248, 1254, and 1260.
Includes aldrin for 1976-77.
industrialized regions of the Northeast and Midwest (Ta-
ble 8). Significant PCB residues (>-1.0 µg/g wet weight)
were typical of fish from most waters contiguous to major
population centers. Trace concentrations of the more per-
sistent, highly chlorinated residues continued to be detected
in fish from almost every major river in the United States.
The ubiquity of PCB iesidues probably results from atmos-
pheric transport, from the dispersal of contaminated sedi-
ment, and from patterns of continued use and disposal.
Cyclodiene Insecticides
Of the cyclodiene insecticides, aldrin and dieldrin have
received the most notoriety. Nationally, mean dieldrin resi-
dues have historically been low (< 1.0 µg1 g wet weight),
compared with residues of DDT and PCB's. Nevertheless,
ANOVA revealed a statistically significant, albeit small,
downward trend in mean dieldrin residues after 1974
(Tables 6 and 7). Analysis of covariance showed significant
declines at eight stations and increases at three stations
during this period (Table 7). However, there was no signifi-
cant change from 1976-77 to 1978-79 (Tables 6 and 7).
Levels were relatively low (<0.2 µg/g) at the stations
showing increases; levels were much higher at many of the
stations with declining residues. Among the group show-
ing declines were stations in the Corn Belt (26, 68, 69, and
83) and in Hawaii (99 and 100). As in 1974, dieldrin resi-
dues were highest in fish from Hawaii (station 100), from
Lake Michigan (stations 104, 105, and 21), and from the
major rivers in the Midwest (Table 8). At station 76 (Mis-
sissippi River at Memphis, Tennessee), elevated levels of
dieldrin, endrin, and other cyclodiene compounds before
1975 were attributed to the presence of a pesticide manu-
facturing facility (Schmitt et al. 1981). However, dieldrin
residues at this station ranked only 11th highest in both
1976-77 and 1978-79 (Table 8), and residues in fish declined
significantly after 1974 (Table 7). Because aldrin is rapidly
metabolized to dieldrin (Schnoor 1981), residues are seldom