Death following exposure to fine particulate nickel from a metal arc process.

A man was taken ill suddenly while spraying nickel using a thermal arc process. He was relieved of his duties and sent home. His condition deteriorated and he was admitted to hospital with a diagnosis of pneumonia. Thirteen days after exposure he died. At post mortem examination the cause of death was determined to be shock lung or Adult Respiratory Distress Syndrome (ARDS). Reproduction of the conditions under which the man had operated the metal arc process produced nickel concentrations of 382.1 mg m-3 in the air next to the operator. Of this nickel, 64.6% was in the form of particles less than 1.4 microns in diameter; the majority being 50 nm in diameter. The total amount of nickel inhaled by the man, who operated the process for 90 min, was estimated to be nearly 1 g. The toxicity of the nickel is thought to be associated with the very fine particulate nature of the metal fume and the large amount inhaled. The importance of wearing adequate protective equipment while operating this metal arc process is stressed.

The transport of aluminum and water across the rat small intestine.

Aluminum transport across the epithelium of the rat small intestine has been investigated to determine factors affecting its absorption and its effect on the transport of other substances across the membrane. The intestines were attached to a perfusion apparatus and perfused with Krebs-Ringer-bicarbonate buffer containing aluminum. The transport of aluminum and buffer ions across the small intestine were measured. Phosphate transport was found to be the most satisfactory marker for viability. It is impossible to accurately measure the aluminum transport across a biological membrane unless the aluminum concentration of the solution is stable over the period of measurement. Hence, the solutions were stabilized with citrate ions which made them stable over a period of at least two hours. The velocity of transport of aluminum across the epithelium increased steadily and only became constant after about one hour. The steady state value of 0.12 micrograms atom of Al/hr/mg dry tissue compares well with that reported in the literature for stable aluminum solutions. Aluminum inhibited the transport of water across the membrane, but the inhibition took about two hours to reach a steady state of about 50% of the control value. This indicates that aluminum-containing medications and foods are able to interfere with the absorption of nutrients from the gut. Aluminum salts may therefore be useful to prevent rapid dehydration in the treatment of certain diseases such as cholera.