Potential risks from the use of MMA arise from repeated exposure. Health issues include asthma, dermatitis, eye irritation including possible corneal ulceration, headache and neurological signs. Another of the low molecular weight sensitisers. Monomer fumes may be absorbed by contact lenses increasing eye irritation.[1]
(5) ANOTHER STERILANT - ETHYLENE OXIDE.
“Acute overexposure to EtO causes conjunctival, skin, and respiratory tract irritation, including rhinitis, cough, and shortness of breath. Headache and nausea may also occur. A questionnaire survey found one or more symptoms in most sterilising operators... Reactive airways dysfunction syndrome (RADS) was reported in a railway worker following 4 days exposure from a leaking container... Several target organs may be adversely affected by chronic exposure, including the respiratory, neurologic, dermal, and hematopoietic systems... Chronic exposure resulting in peripheral neuropathy...decreased performance on neuropsychologic testingmemory loss, mild cognitive impairment...atrophy...evidence of axonal degeneration on sural nerve biopsy in one...”[2] A 1982 Finnish study using data from a postal questionnaire and a hospital discharge register showed that in pregnant staff using ethylene oxide for sterilising procedures, frequency of spontaneous abortion was 16.7% compared with 5.6% for non-exposed pregnancies. This increase did not correlate with exposure to gluteraldehyde or formaldehyde, “although glutaraldehyde may not be absolutely safe... Similar increases were seen when one of the two agents was used in combination with other... Exposure to formaldehyde in the sterilisation units may have been minimal particularly when gas chambers are used.”[3] The most recent classification of EtO is as a carcinogen - (International Agency for Research on Cancers, 1994). If ethylene oxide is used to sterilise heat sensitive devices, they must be dry as ethylene glycol (see X-ray chemical notes) forms in combination with water. (Kay Ball, Nurse Educator, address to NZ Perioperative Nurses’ Conf, Nov 1998).
SYNERGISTIC EFFECTS - THE COCKTAIL
Many of the Xray and theatre chemicals are individually dangerous and the synergistic effects are unknown. Synergism is the simultaneous action of separate agencies which, together, have greater total effect than the sum of their individual effects, for instance, alcohol significantly increases the effects of lead. The phenomenon is readily seen in the impact of drugs, but never mentioned on Material Safety Data Sheets required for the sale of toxic chemicals in the United States by the Environmental Protection Agency. US lawyer Richard Alexander writes:“Rarely can an MSDS be found that discusses harm from chronic exposures and equally rare is any mention of the synergistic effect of chemicals. Open any of these Material Safety Data Sheet sites to confirm that fact” :
*Material Safety Data Sheets at Oxford University, UK http://physchem.ox.ac.uk:80/MSDS
*Material Safety Data Sheets at Case Western Reserve http://research.nwfsc.noaa.gov/msds.html
Glutaraldehyde and formaldehyde when combined to fix tissue in electron microscopy were much more potent than when used individually.[4] Glutaraldehyde combined with the effects of other sterilants and anaesthetic gases in theatres is uninvestigated. Formaldehyde may be used to preserve specimens and as a sterilant. In radiology and theatre it may also be off-gassing from unsealed particle board shelving etc, carpets and furnishings. Methanol (which metabolises to formaldehyde in the body) was detected in significant quantities in the headspace above GA sterilising solutions. Butyraldehyde was detected above GA solutions in both X-ray and theatre. Theatre nurses may also have had exposure to methylmethacrylate - used to glue bones to new joints. Add in to the radiographers’ cocktail other previously listed X-ray processing chemicals including hydroquinone (phenol), glycols, 5-nitroindazole, and the other corrosive and caustic chemicals (all potentially present in an aerosol), plus the toluene, sulphur dioxide, and acetic acid detected, plus silver, and remember that most radiographers and nurses used no gloves/skin protection let alone respiratory protection. Solvent uptake through skin depends on duration of contact, skin thickness, perfusion and degree of hydration, and the presence of cuts, abrasions or skin diseases. Frequent washing with harsh disinfectants damages the skin barrier. (Goetz, 1985). Many radiographers worked in small rooms which had no ventilation whatsoever.Quite often ventilation was into the ceiling or into unconnected ducts. Many nurses worked in unventilated theatres.
Other VOCs (volatile organic compounds) may be present - these are the components of “sick” or “tight” buildings including solvents from air fresheners (see paper on p. 38) as well as fragrance products - perfumes and strong deodorants; also phenol, bleach and ammonia from cleaning. In X-ray, Scobbie et al also detected benzenes, traces of phthalates (used in making plastics) and trace phenols.
[1]Auckland Occupational Safety and Health Associates. Letter. 30 July, 1998.
[2]Weaver V M. Chemical hazards in health care workers. Occ Med. 1997, 12, 4, 655-667.
[3]Hemminki K et al. Spontaneous abortions in hospital staff engaged in sterilisinginstruments with chemical agents. British Medical Journal. Vol 285, 1461-1463. 1982
[4] Kirkeby S. and Moe D. Studies on the actions of glutaraldehyde, formaldehyde and mixtures of glutaraldehyde and formaldehyde on tissue proteins. Acta Histochem. 79, 115-121 (1968)
