Pb-210 dating of two metal-polluted organic sediment cores obtained near a former pyrometallurgical zinc smelter in Lommel, Belgium have been used to reconstruct atmospheric lead deposition rates during the 20th century. Independent knowledge concerning historical pollution events and 137Cs fall-out profiles has allowed a critical evaluation of the CRS, CIC and CF-CS models for the 210Pb age interpretation. Resulting ages for the three models suggest that, in this case, the CIC model gives the most accurate interpretation of historical pollution events and atmospheric lead fall-out. The 210Pb water-sediment flux was estimated at 141-1158 Bq·m-2·yr-1 for one site and 62-106 Bq·m-2·yr-1 at the other site, during the last century. The large difference illustrates that sediment focusing was important on a small spatial scale (10 m). The direction of focusing correlates with the predominant wind direction. Maximum atmospheric lead deposition rates were found to be 1.63 ± 0.59 g·m-2·yr-1 around 1968 AD, which is 2 orders of magnitude larger than the Belgian average in 1980 AD, and 5 orders larger than Holocene atmospheric lead deposition.