TIME TREND AND DETERMINANTS OF BLOOD LEAD LEVELS IN A SWISS POPULATION OVER A TRANSITION PERIOD (1984-1993) FROM LEADED TO UNLEADED GASOLINE USE

This study analyzes the trend and determinants of blood lead levels in a Swiss region (population 770,000) over the 10-year period following the introduction of unleaded gasoline in 1985. The consumption of unl eaded fuel increased rapidly, accounting in 1988 for 36% and in 1992 f or 65% of all gasoline sales. Blood lead levels were measured in three representative samples (n = 1700) of the adult population within the framework of a health examination survey carried out in 1984/1985, 198 8/1989, and 1992/1993. The geometric mean blood lead levels were, resp ectively, 0.59, 0.42, and 0.33 mu mole/liter in men, 0.41, 0.29, and 0 .25 mu mole/liter in women. Similar trends have been observed across a ll age groups, occupational classes, and categories based on smoking, drinking, and dietary habits. The overexposure of city residents, in c omparison to village residents, fades out over the observation period. These findings suggest that the changeover from leaded to unleaded ga soline has been the major cause of the blood lead decline. Wine drinki ng, cigarette smoking, and age appear to be significant determinants o f blood lead for both sexes in all three surveys. In contrast, the ass ociation is inverse for milk consumption. The multivariate regression analysis shows that wine drinking remains the most important predictor of blood lead, whereas the influence of age increases with time and o vercomes the effect of smoking in the third survey. (C) 1995 Academic Press, Inc.