MacGREGOR: AMOUNT AND PROPORTIONS OF DDT 



There was also a large decrease between May 

 1970 and January 1972, in total pesticides in the 

 fish taken in Santa Monica Bay (Table 4). The S. 

 paucispinis taken in 1972 were smaller than those 

 taken in 1970 which may account in part for the 

 lower values. The five specimens taken in January 

 1972, averaged 312 mm total length. Phillips 

 (1964) gives the total length of this species at age 2 

 as 267 mm and at age 3 as 343 mm. Thus, most of 

 the growth of these specimens had taken place 

 since dumping stopped. 



On land where soil has been subjected to DDT 

 spraying for long periods of time, the situation is 

 very different. In New York State vineyard soils 

 (Kuhr, Davis and Taschenberg, 1972) the residues 

 consisted of 73% DDT and 27% DDE after 24 yr of 

 spraying with DDT. In Oregon (Kiigemagi and 

 Terriere, 1972) samples of soil from one orchard 

 contained 80%DDT, 17%DDE, and 3%DDD after 

 25 yr of spraying, while soil samples from another 

 orchard in a different area contained 78% DDT, 

 14% DDE, and 8% DDD after 24 yr. Forests in New 

 Brunswick, Canada (Yule, 1973) were sprayed 

 heavily from 1956 to 1967 in which year spraying 

 with DDT ceased. Many samples taken of soils in 

 this area in 1968 contained 92% DDT and 8% DDE. 

 Three years later a second sampling of the soils in 

 the same locality contained 90% DDT and 

 10% DDE. DDD was present only in trace amounts 

 in both sampling years. 



As a general rule soil samples from land areas 

 that have been sprayed with DDT tend to contain 

 a much higher proportion of DDT than DDE or 

 DDD even after many years. This is not neces- 

 sarily true of the fauna that inhabit the land un- 

 less their contamination is the result of recent 

 spraying. Keith and Hunt (1966) give examples of 

 a number of species of mammals and birds in 

 which the proportions of the three analogs vary 

 greatly. 



Within some species of birds, which are more 

 wide ranging than mammals, there seems to be 

 remarkable uniformity in the proportions of the 

 three analogs. Martin and Nickerson ( 1972 ) tested 

 125 10-bird samples of starlings from throughout 

 the (48) United States. These samples averaged 

 91%DDE, 3% DDD, and 6% DDT. Although the 

 total residues ranged from 0.05 to 15 ppm, in only 

 two samples did the amount of DDD exceed DDT, 

 and in only one did the amount of DDT exceed 

 DDE. 



The proportions of the three analogs of DDT in 

 the starlings is very similar to the proportions 



found in the fish taken in Santa Monica Bay in 

 1970 (Table 4), in the porpoises found dead on the 

 beach in 1970, and the small fishes and inverte- 

 brates taken off Los Angeles in the mid-water 

 trawl in 1971 (Table 5). And, in fact, except in 

 cases of recent contamination by DDT, most fauna 

 have tended to approach these proportions in re- 

 cent years. This is in spite of the fact that soil 

 samples from areas of land that have long his- 

 tories of spraying with DDT almost without excep- 

 tion contain very high proportions of DDT. From 

 this it would appear that the selective storage, 

 metabolism, and excretion of DDT is somewhat 

 similar for all animals. 



When investigators first became aware of the 

 pesticide problem, methods of measuring residues 

 were considerably less refined than they are at 

 present, and few samples were run. Very little 

 work has been done on preserved specimens from 

 these earlier years. But, in view of the similarity 

 in proportions of DDE and DDT in so many differ- 

 ent species in recent years, it seems probable that 

 the increase in DDE and the change in ratios of 

 DDE and DDT inS. leucopsarus are descriptive of 

 the general change in these analogs that has 

 taken place in the earth's environment. 



There was no pattern discernible in the dis- 

 tribution of Aroclor 1254. In 472 myctophid sam- 

 ples taken between 1949 and 1966, the median 

 values of Aroclor 1254 fluctuated around 0.17 ppm 

 and showed no trend with time. Sixty-eight per- 

 cent of the samples contained less than 0.25 ppm. 

 The only indication of an areal relationship was 

 that while the three stations closest to the White 

 Point sewer outfall, and the city of Los Angeles 

 (CalCOFI stations 87.35, 90.28, and 90.30) consti- 

 tuted only 8% of the total samples, they accounted 

 for 34% ( 12 out of 35) of the myctophids containing 

 more than Ippm of Aroclor 1254. However, there 

 were some samples taken 175-200 nautical miles 

 offshore that contained more than 1 ppm, and 

 there were others taken near shore in the Los 

 Angeles area that contained none or traces only. 

 These higher values could result from the myc- 

 tophids ingesting nondigestible particles of 

 man-made substances either while feeding or ac- 

 cidentally while in the cod end of the plankton net. 



In the larger fish taken in the Los Angeles area, 

 the high values of the DDT residues tend to mask 

 the presence of Aroclor 1254. What might be re- 

 corded as a trace amount could actually be a 

 rather significant amount in view of the dilute 



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