Urban stormwater pollution in Genoa, Italy was studied by monitoring runoff from roofs and roads. The researchers found that road runoff had high levels of pollutants like suspended solids and COD, while zinc was a concern in roof runoff. The first flush phenomenon, where pollutants are washed off early in a rainfall event, was observed in most cases. Rainfall intensity and environmental conditions influenced the amount of pollutants in the runoff. The study showed a strong correlation between COD and suspended solids concentrations in the water. Overall, the findings suggest that urban surfaces contribute to water quality deterioration in the area.