DDT in humans

Reference ranges have been established for arsenic, lead, cadmium, mercury, platinum, nickel in blood and urine pentachlorophenol and metabolites of organophosphorus in serum and urine PCBs, fi-HCH, HCB, DDE in blood organochlorine pesticides (fi-HCH, HCB, total DDT) in human milk... 

Table 10.8 DDT in human milk from around the world (from Shaw et al., 2000) ...

Table 10.9 DDT in human milk from four Indonesian women volunteers...

Hattula, M.L., Ikkala, J., Isomaki, M., Maatta, K., Artila, A.U., 1976. Chlorinated hydrocarbon residues (PCB and DDT) in human liver, adipose tissue and brain in Finland. Acta Pharmacol. Toxicol. 39, 545-554. 

Figure 18.16. Concentrations of DDTs in human breast milk collected from general public in Asian countries. References cited are similar to those in Fig. 18.15.

Fig. 18. DDT in human milk Highest reported concentration of DDT in human milk by country (from WHO, 2004c).

Dorner G and Piagemann A (2002) DDT in human milk and mental capacities at school age an additional view on PISA 2000. Neuroendrocrinol Lett 23 427-431. 

The cyclodienes, particularly aldrin, dieldrin, and endrin, are considered unsafe for any kind of use. Lindane, on the other hand, has high selectivity in favour of Man. It is included in the World s principal pharmacopoeias as an insecticide, acaricide, and larvicide. A 0.2% alcoholic solution is applied topically for head lice and a 1 % emulsion is employed in the treatment of scabies, in humans. The use of DDT in human medicine, for similar purposes, has greatly diminished in the last decade. It must, however, be pointed out that it has a high safety record in Man, and that government bans on its use are concerned with its accumulation in the food chains of birds and fish where it interferes with the calcium metabolism of shells and bones, respectively (see p. 96). In 1956, Hayes, Durham and Cueto, of the USA Public Health Service, fed 35 mg of DDT per man per day (i.e. 200 times the highest average dietary intake of that time in the USA) to human volunteers for 18 months. None of the subjects developed any symptom related to this chemical. 

Residue Levels of Polychlorinated Ter-phenyls. Polychlorinated Biphenyls and DDT in Human Blood Bull. Environ. Contam. Toxicol. 13(1) 57-63 (1975) CA 82 107215u... 

While the absolute toxicity of a chemical can vary by orders of magnitude from species to species, the relative toxicides of chemicals tend to be more conserved through evolution. Thus if chemical B is more toxic than chemical A in rats, and A is more toxic than C, the same order of toxicity, B > A > C, is likely to hold in humans, as well. Because of the greater evolutionary conservation of relative toxicides, LDjg values in rats in effect provide an approximate scale for ballparking the relative toxicides of chemicals in humans. For example, strychnine is 50 times more lethal than DDT in rats (Table 5.2), and therefore it is reasonable to infer that strychnine is probably on the order of 10 to 100 times more lethal than DDT in humans. The availability of scales of reladve toxicides in a few species, such as rats, fathead minnows, ring-necked pheasants, and water fleas, are valuable for inferring relative toxicities in related species. 

The value of insecticides in controlling human and animal diseases spread by insects has been dramatic. It has been shown that between 1942 and 1952, the use of DDT in pubHc health measures to control the mosquito vectors of malaria and the human body louse vector of typhus saved five million hves and prevented 100 million illnesses (4). Insecticides have provided the means to control such important human diseases as filariasis transmitted by Culex mosquitoes and onchocerciasis transmitted by Simulium blackflies. 

DDT is slowly converted in vivo by reductive dechlorination to DDD and by further dechlorinations to 4,4 -dichlorodiphenylacetic acid [83-05-6] (DDA), the predominant excretory metaboUte. Anaerobically, it may form 4,4 -dichlorodiphenyiacetonitrile [20968-04-1] (DDCN). However, most DDT that enters the environment is sequestered as DDE, which is ubiquitously present in the body Hpids of invertebrate and vertebrate animals. In humans. 

UV filters are currently considered as emerging environmental contaminants of increasing concern since most of the commonly used are known to cause endocrine disrupting effects in both aquatic and terrestrial organisms as well as in human skin cells [4]. These compounds bioaccumulate in fish at similar levels to polychlorinated biphenyls (PCBs) and DDT [5, 6]. 

Humans are also at the top of food webs, and by the late 1960s citizens of several countries were horrified to learn that the levels of DDT in mothers milk ranged up to 130 ppb, which would have been classified as unfit for human consumption. 

A review on the usage of POP pesticides in China, with emphasis on DDT loadings in human milk M.H. Wong, A.O.W. Leung, J.K.Y. Chan and M.P.K. Choi. 

R. P. Moody, B. Nadeau, and I. Chu. In vitro dermal absorption of pesticides VI. In vivo and in vitro comparison of the organochlorine insecticide ddt in rat, guinea pig, pig, human and tissue-cultured skin. Toxicol. In vitro 8 1225-1232 (1994). 

DDT exposure to human cancers. The lARC has determined that there is sufficient evidence for the carcinogenicity of DDT in experimental animals and that it is possibly carcinogenic to humans. ... 

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