Sand contamination is an important factor when assessing the health hazard potential of public beaches. The goals of this study are
to assess the performance of four sand washing procedures on the removal of surface adsorbed chemical species, and to identify
which chemical components are best suited for monitoring the health quality of beach sand. Four washing treatments were
investigated: contact, stirring, sonication, and boiling. Sand samples were collected from three Portuguese beaches and the wash
water analysed. The observed variables were specified in two main groups: 1) physicochemical parameters comprising sulphates,
pH, and conductivity; and 2) pollution indicators including nitrogen and phosphorous chemistries, chemical oxygen demand
(COD), and oxidability. The Group I measurements did not exhibit significant differences with sand treatment (p=0.89), but there
were differences in the Group II measurements due to the higher COD and oxidability values (p<0.01). The best extraction yield
was obtained with sonication. In terms of a suitable health quality marker, neither group exhibited significant variation with beach
location or sampling period of year. Individually, however, several chemical parameters were found to be significant on the basis
of sampling period (p < 0.01) and beach location (p < 0.001). The COD and oxidability values were also found to vary significantly
on the basis of sampling period (p < 0.01 and p< 0.001, respectively). COD was determined to the best sand quality indicator.