Bromism Expected in Environmentally Friendly Dry Cleaners

Neurologic symptoms caused by occupational exposure to the solvent 1-bromopropane (ie, bromism) are anticipated to rise. This warning, presented in the latest issue of the MMWR, is in response to 2 recent case reports and an expected increase in the use of 1-BP as a substitute for ozone-depleting compounds (eg, chlorofluorocarbons), particularly in the electronics and dry-cleaning industries.

In one case, a 50-year-old man, who worked directly with 1-BP at an electronics plant, developed persistent cognitive dysfunction and a sensory neuropathy. Medical evaluation revealed a significantly low anion gap and an elevated serum bromide level, characteristic of bromide toxicity. OSHA-sampled air at his workplace, where he did not use personal protective equipment (PPE), was considerably elevated above that recommended by professional organizations.*

The second case was a 43-year-old dry cleaner who experienced a number of neurologic symptoms, including headache, visual problems, paresthesias, and muscular twitching, after working with 1-BP (DrySolv) without PPE. The air in his work environment also revealed high levels of 1-BP.

The MMWR advises that physicians should remain vigilant for the possibility of 1-BP toxicity, especially in employees of dry-cleaning businesses (estimated at 110,000 Americans) as they transition from the use of the solvent perchloroethylene to the more environmentally friendly 1-BP. In some states—eg, California and New Jersey—this transition has been mandated by legislation. The substitution of 1-BP for perchloroethylene at dry-cleaning operations requires substantial modifications to equipment, such as the upgrading of vapor-control systems, which small businesses may not readily accommodate.

Historically bromism was seen in individuals who consumed the old sedative bromides chronically or in large amounts. More recently bromide toxicity could be seen after exposure to methyl bromide gas, a fumigant insecticide and an ozone-depleting compound that is also being phased out. Acute intoxication causes malaise, nausea, vomiting, followed by visual disturbances, mental dysfunction, ataxia, tremor, myoclonus, and seizures. Chronic exposure can cause neuropathy, cerebellar dysfunction, and symmetric brain lesions on MRI.

The mechanisms by which bromide causes neurologic dysfunction are unknown; however, it is speculated that clinical bromide toxicity may be manifestation of an "energy deprivation syndrome," in which metabolic pathways are disrupted—an explanation that's about as satisfying as diagnosing "toxic-metabolic encephalopathy" (ICD-9-CM 348.31).

OSHA = Occupational Safety and Health Administration. 

* OSHA does not presently have a permissible exposure limit for 1-BP.

David's rendering of polluting dry cleaners from the National Institute of Environmental Health Sciences.