Abstract

An investigation was carried out in an aluminium recovery works after the simultaneous occurrence of haemolytic anaemia in two workers in the slag disposal plant.

The first worker was admitted to hospital suffering from nausea, backache, and haematuria. Jaundice developed on the next day. His urine contained protein, urobilin, haemoglobin, and methaemoglobin but no red cells. During the course of his illness the haemoglobin was reduced to 6·8 g./100 ml. There was no abnormality of the blood film and red cell fragility was normal.

A fellow worker was affected at the same time and was treated at home for the same symptoms. Examination five days later showed a haemoglobin level similar to that of the first worker.

He had suffered the same symptoms eight years previously, and at this time another worker had suffered from jaundice at home and a third had been investigated for neurological symptoms.

Ten years previously another worker had been admitted to hospital with anaemia, jaundice, and haemoglobinuria.

At this works scrap aluminium is melted with sodium chloride and fluorspar as a flux. The slag from the furnace is later broken up and dissolved in a rotating drum by a stream of water. The soluble portion is carried into a lagoon, whilst the 3% aluminium is retained in the drum and discharged weekly. Two men are employed at a time and another six have been employed in the past 10 years.

Five parts per million of arsine were found to be present in the atmosphere during slag washing, but higher levels would have occurred on the occasions when slag from the making of an aluminium copper alloy from copper with an arsenic content was similarly treated.

The mechanism of arsenic production is discussed and the literature on the role of aluminium reviewed.