An experimental ecotoxicological study and its application to the behavioural study of organic mercury (CH3HgCl) in the environment: influence of temperature and pH.

Laboratory experiments were carried out to study the influence of temperature (24, 28 and 30 degrees C) and pH (1-10) on organic mercury (CH3HgCl) transfer and accumulation in an experimental ecotoxicological model. We followed the evolution of CH3HgCl in a basic model (water + air) by varying temperature and pH. In a second step, we completed the model by adding sediment and fish.

Determination of total mercury in estuary, lake and river sediments.

In order to improve the quality of the results in sediment analysis, the Community Bureau of Reference (BCR) of the European Communities has developed 3 sediment reference materials (CRM) from estuarine, lake and river origins. Certification of mercury content in these materials was achieved by 3 methods (cold vapor atomic absorption spectrometry, plasma emission spectrometry, neutron activation analysis with radiochemical separation). The values finally certified in the CRM estuarine, lake and river sediments are 1.

Study of mercury content in edible mushrooms.

The influence of time and temperature of mineralisation of mushrooms was studied for mercury determination by cold vapor atomic absorption. Optimal conditions for a complete mercury recuperation were obtained using a mixture of nitric and sulphuric acid (6 ml HNO3, 4 ml H2SO4) in presence of KMnO4 (3 ml of a 0.44 M solution) at 95 degrees C for 4 h, with 1 g wet sample.

Lung and blood superoxide dismutase activity in mercury vapor exposed rats: effect of N-acetylcysteine treatment.

Rats were exposed to mercury vapors (30 mg/m3) for either 1 or 2 h. Histological lesions like alveolar oedema, hyaline membranes and sometimes fibrosis were observed. The lesions were more significant after 2 h of exposure, with about 50% of the animals dying within 2 weeks.

Acute mercury chloride intoxication. Effects of hemodialysis and plasma exchange on mercury kinetic.

A 27 year-old man developed after ingestion of mercury chloride, 6 g, a hypovolemic shock, an acute renal failure and a necrosis of the stomach which required a total gastrectomy. The anuria did not improve and required 42 hemodialyses. Subsequent evolution showed numerous complications and the patient died on the 91st day.