The spectrum of respiratory disease associated with exposure to metal working fluids.

Occupational respiratory diseases have been reported following exposure to metal working fluids. We report a spectrum of respiratory illnesses occurring in an outbreak in 30 workers of an automobile parts engine manufacturing plant. Workers presented with respiratory complaints and, after clinical and laboratory evaluations, were classified as those having hypersensitivity pneumonitis, occupational asthma, or industrial bronchitis, or those without occupational lung disease. Hypersensitivity pneumonitis affected seven workers, with six exhibiting serum precipitins to Acinetobacter Iwoffii. Occupational asthma and industrial bronchitis affected 12 and six workers, respectively. Oil-mist exposures were below current recommendations. Gram-negative bacteria, but no fungi, Thermophiles, or Legionella, were identified. Although specific agents responsible for each individual case could not be identified, probably both specific sensitizing agents and non-specific irritants from metal working fluids, additives, or contaminants contributed to this spectrum of occupational respiratory illness.

Effects of thyroidectomy, parathyroidectomy and lithium on circadian wheelrunning in rats.

Circadian rhythms and levels of wheelrunning were studied in thyroidectomized, parathyroidectomized, thyro-parathyroidectomized, and sham-operated male rats. Animals were entrained to a 12:12 light:dark schedule, then exposed to constant dim red illumination, and then given a diet containing lithium. Under constant conditions, free-running circadian activity rhythms were shorter, and levels of activity were greater, in thyroidectomized and thyroparathyroidectomized animals. Lithium reversed these effects, lengthening free-running circadian periods in all groups, with a greater reduction of activity observed in animals with thyroids removed. Parathyroidectomy had no clear effects. Since lithium slowed circadian rhythms and reduced activity even in the absence of intact thyroid or parathyroid glands, these effects may have been due to the action of lithium at some other site. The same may be true of other thyroid suppressors reported to affect circadian rhythms. These findings may be relevant to the biological substrates of major affective disorders in humans, which have been associated with abnormalities of thyroid function, abnormally short circadian rhythms, abnormal activity levels, and responsiveness to lithium therapy.