DDT

50-29-3

Insecticide, nematocide. 
Mainly in tropical devoloping 
countries.

Odor threshold: detection: 0.35 mg/kg water (Sigworth 1964).

354.48

Equilibrium distribution:
         mass %
air      0.40
water    0.42
solid   99.18
(Anon 1988)

Degradation very slow in sunlight: 34 % in 7 days (>290 nm)
(Gäb et al. 1975).

Photooxidation half-life in air:
17.7d - 177d,
scientific judgement based upon estimated rate constant for
reaction with hydroxyl radical in air (Howard 1991).

Permanent in sunlight (in river water) for 8 weeks. 
In tropical
conditions, photochemical degradation is faster (Eichelberger &
Lichtenberg 1971).

Photooxidation by u. v. lihgt in aqueous medium at 90 - 95 °C:
time for the formation of CO2 (% of theoretical)
             25 %:  25.9 hr
             50 %:  66.5 hr
             75 %: 120.0 hr (Verschueren 1983)


Photooxidation half-life in water: 
7d - 350d, 
scientific judgement based upon measured rate constant for 
reaction with hydroxyl radical in air (Howard 1991).

First order hydrolysis half-life:
22yr, calculated from measured base catalyzed hydrolysis
constant (Howard 1991).

Permanent in static bottle test (28 d) (Tabak et al. 1981);
although very slow degradation to DDD (Kobayashi & Rittmann
1982).

Aerobic half-life:
2yr - 15.6yr, based upon observed rates of biodegradation in
aerobic soils under field conditions (Howard 1991).

Anaerobic degradation to DDD (Guenzi & Beard 1968).

Anaerobic half-life:
16d - 100d, based upon anaerobic flooded soil die-away study
for two flooded soils (Howard 1991).

75 - 100 % disappearance from soils: 4 - 30 years
(Edwards 1966).

In river water: 100 % of original compound found after 8 weeks
(Verschueren 1983).

Biodegradation:
0% by BOD
period: 14d
substance: 100 mg/l
sludge: 30 mg/l
(MITI 1992)

Degradation products of special interest: DDE, DDD,
3-methylsulfonyl-DDE (very toxic in mammals) (Lund et al. 1988).

A metabolite 3-methylsulfonyl-DDE is found in seals. 
The
chemical is persistent and strongly toxic after metabolic
activation (Jensen & Jansson 1976, Lund et al. 1988).

DDT induces MFO-enxymes in liver in birds and mammals
(WHO 1979).

Confirmed to be accumulated on a high level (Anon. 1987).

Bioconcentration factor (mammals):
37000000, sea water/dolphin (Virtanen & Nuuja 1987).

Bioconcentration factor (mollusca):
700 - 70000, (Verschueren 1983).
70000, oyster (Weber 1977).
15000, sum of DDT (Verschueren 1983).
  
Bioconcentration factor (crustaceans):
12100, sea water/zoopl. (Virtanen & Nuuja 1987).
20000, Daphnia (Kenaga & Goring 1980).
  
Bioconcentration factor (algae):
4720 - 80000
 
Bioconcentration factor (other organisms):
80000, Amphidinium (Cox 1970).

3-methylsulfonyl-DDE: mouse, acute injuries in adrenal glands 
(Lund et al. 1988).

Man, 0.5 mg/kg, per day, during 21 months, no harmful effects 
(Martin 1968).

NCI carcinogenesis bioassay completed: results negative,
mus,rat (Lewis & Sweet 1984).

No carcinogenic effects in humans after 1300 months, 10 - 20
years (Rippen 1988).

Negative in the Ames test (van Dijk & van de Vorde 1976).

Ring-dove, DDE induces thinning of the eggshell and impaired
reproduction (Moriarty 1988).

Removal/secondary treatment:
100%, removal percentage based upon data form a continuous
activated sludge biological treatment simulator. 
(Howard 1991).

Cyprinus carpio; 0.01 mg/100g/day; 10 d, biochemical effect
(change in physiochemical process including glycogen uptake,
cholesterol levels and lipid analysis) (Kobayashi et al. 1987). 
Tilapia mossambica; 0.001 mg/l, 20 d, histological effect
(presence of physical damage to tissues) (Shukla & Pandey 1986).

LC50, 24 hr, Chironomus, 0.0047 mg/l (Estenik & Collins 1979).

LC50, 10 d, 3.98 mg/l, Phagocata gracilis (Bonner & Wells 1987).

LC50, 96hr, 0.007 mg/l, 15 °C, Pteronarcys, second year class;
LC50, 96hr, 0.0012 mg/l, 15 °C, Isoperla, juvenile; LC50, 96hr,
0.0074, 15 °C, Chaoborus, juvenile (Johnson & Finley 1980).

The p,p'-isomer appears to be more toxic than the o,p-isomer to
invertebrates. 
DDE is one of the primary metabolites of DDT in
invertebrates and produces biological effects similar to those
of the parent compound. 
DDT rapidly accumulates in
invertebrates to several thousand times the exposure level in
concentrations as low as 80 ng/l. 
The residue half-life was 7
days in Daphnia. 
A 60 % reproductive impairment was observed in
Daphnia at 0.100 mg/l. 
No difference in toxicity was noted
between hard and soft water. 
Although isomers tested were toxic
to rainbow trout sac fry, the more polar compounds appeared
more toxic than the less polar ones. 
DDT detrimentally altered
several physiological characteristics, including normal ratios
of serum amino acids, thyroid activity, and the ability to
withstand stress. 
Food seems to be more important than water as
a source of body residues. 
Although DDT was not observed to
affect gonad maturation, the mortality of fry produced by
treated parents was high, especially during the terminal stages
of yolk absorption (Johnson & Finley 1980).

The toxicity increases when the hardness of water increases
(Bergling & Dave 1984).