This article is a commentary on the following study: Maresky LS, Grobler SR. Effect of the reduction of lead in gasoline on the blood lead levels of South Africans. Sci Total Environ. 1993 Aug 15;136(1-2):43-8. This study shows, like many others, the very positive impact of removing lead from gasoline on reducing blood lead levels in the population. It should be noted, however, that this study is not recent and that, regarding the issue of lead in the atmosphere, many developments have been observed since then, particularly in Europe. The findings from the past are therefore likely no longer valid regarding current blood lead levels in urban populations across European countries. Some methodological criticisms can be raised. It would have been interesting, to better compare and understand the measured blood lead levels, to correlate them with atmospheric lead concentrations. At no point, in fact, does the article mention lead levels in the air, whether in urban background conditions (as in the sample studied) or near road traffic (as in the case of truck drivers tracked in previous studies). This lack of reference is likely due to the absence of in situ measurements. Only such characterization would provide an idea of the exposure caused by all sources of urban pollution, and not just road traffic, even though the latter is clearly a dominant source. The variability in blood lead levels observed within the samples is puzzling for subjects presumed not to be exposed to specific sources of lead. No information is provided on the precision of blood lead level measurement using the micro-method, which could partly explain the variability in the results. The sample is assumed to be unaffected by "known" sources of lead, though no specific details are provided on this point. The authors do not specifically address other local sources of lead contamination, whether in the home or in the outdoor environment (paint, specific industrial sources). The representativeness of the sample relative to the city’s urban population is unknown. It is not indicated whether there are differences between the two samples regarding confounding factors such as age and sex. Other possible causes of the decrease in blood lead levels are not addressed (notably diet). Furthermore, the doubts raised regarding the cost-effectiveness of continuing to reduce the lead content in gasoline are not substantiated and go beyond the scope of the study. There is no data on the cost of alternative solutions. The acceptability, from a public health perspective, of the population’s blood lead levels estimated by the study is not sufficiently argued in the absence of a recognized no-effect threshold for lead. The argument that blood lead levels in the general population of Cape Town are lower than those found in industrialized regions of countries that have banned lead in gasoline is open to criticism. The situation of individuals with additional sources of exposure is not discussed. Finally, the situation of children—who are not included in the study but constitute the population most at risk—is not addressed. (Comment)