Application of blood cadmium analysis to industry using an atomic fluorescence method

A flame photometric method using atomic fluorescence (AFS) for cadmium (Cd) estimation is described and applied to the measurement of Cd in blood. The AFS system employs a modified, low cost atomic absorption spectrophotometer, with a high intensity Cd light source provided by an electrodeless discharge tube, excited in a thermostatted microwave cavity. The analytical sensitivity of the technique is sufficient to permit dilution (1 in 5) of blood, before aspiration into the air-hydrogen flame. The method is rapid (25 duplicates/hour), and gives acceptable precision (coefficient of variation within batch 2-5%, between batch 8-1%). The method was applied to a reference population and to three different groups of industrial workers. The reference population had a mean blood concentration of 35-1 nmol Cd/litre. Group 1 (general categories of worker) had 65-2 nmol Cd/1, Group 2 (demolition workers), 137-9 nmol Cd/1, and Group 3 (shipbreakers), 105-9 nmol Cd/1. There was a relationship between increases in blood Cd and in blood Pb which was statistically significant for Group 3.