Changes in pattern of organochlorine residues in blood of general Israeli population, 1975-1986.

This study reviews data on the changes with time of the blood levels of some organochlorine compounds (OCCs) in the general Israeli population. All the studied OCC residues, except for p,p'-DDD, were significantly lower in 1985-1986 than in 1975. A decline in blood residues of organochlorine pesticides was observed mainly in the second half of the 1970s, whereas a fall in the polychlorinated biphenyl residue levels took place in the first half of the 1980s. During the latter period, unexplained increases in p,p'-DDD, dieldrin and heptachlor epoxide residue levels were seen. A significant decrease in the blood levels of OCCs quickly metabolized in the body (p,p'-DDT, tetrachlorobiphenyls) indicated a considerable reduction of environmental exposures. The clear decline in OCC contamination of the environment and, in particular, of the human body during the reviewed period (1975-1986) resulted from the restrictions imposed in Israel on the use of OCCs. Nevertheless this does not mean that this problem has been solved. Some health implications of low-level life-long OCC exposure are discussed, and further environmental and biological monitoring and control measures are recommended.