Public Health Minister Pradit Sintavanarong said it would be the second check of marine life to measure the level of pollutants, if any, especially polycyclic aromatic hydrocarbons (PAH) and four heavy metals: mercury, cadmium, lead and arsenic.
In the first round of random checks on July 31, technicians found the level of pollutants in marine life to be below the maximum standard.
Dr Pradit said health officials have also checked the urine of 1,928 cleanup workers, government and company employees as well as volunteers, who cleaned the oil slick on Rayong beaches.
Of the 1,928 checked, with 1,419 known results, only one tested over standard and was under care of doctors, but the patient's overall condition was normal. Blood test and lung x-ray will be later conducted.
Among 1,089 people who received first-aid treatment at Phrao Bay on Samet Island, 337 were given urine tests after suffering from headache, nausea and sore throat, the minister said.