Acryl compounds are various chemicals within a large group. They are
used in medicine and household. Acryl compounds are: acryl acid, methacryl
acid (MAA); their derivates (ethers, amides, nitriles and others); polymers
and co-polymers on their base. Until now there was a few studies on occupational
medicine problems arising at acryl compounds manufacture. These studies
did not reflect all the importance of the problem.
Results
It was established that workplace air at acryl monomers producing plants
was polluted by mixture of chemicals, mainly with acryl and methacryl acids
or their ethers and alcohols (methyl and butyl alcohols). Simultaneously
vapors of cyanides (hydrocyanic acid, aceto- and ethylencyanohydrins, acrylonitrile),
acrolein, aerosol of sulfuric acid and others were found at the same workplaces,
it depended on acryl monomer producing technique. The highest level of
ethers concentration was found at MMA producing plants, but at MA producing
shops this level was lower. Methanol was found more often and in higher
concentrations than butyl alcohol. The lowest level of ethers and butyl
alcohol vapor was found at plants producing less volatile BA and buthyl
methacrylate (BMA). Main occupational hazard was exposure to monomers in
departments where acryl polymers and co-polymers were produced. MMA air
concentrations often were 3-10 times higher than maximum allowable concentration
(MAC) at organic polymer glass shops, especially in moulding and polymer
preparation departments. There were lower concentrations of monomers vapors
(MMA, BMA, MAA, BA, MA) (as a rule at MAC level) at plant where had produced
PMMA suspension, emulsions, polybuthyl methacrylate (PBMA), dacryl, methaclyl
co-polymers and industrial goods of PMMA. It is possible that air is polluted
by polymer dust at final stages of polymers producting.
Main causes of work environment pollution are the following: insufficient
hermeticity of equipetment due to technical imperfection and corrosive
properties of organic acids and other chemicals; manual work; low effectiveness
of local ventilation; high pressure and high temperature in apparatuses;
opening of apparatuses for cleaning from polymers masses formed by spontaneous
polymerization.
Accompanying unfavourable occupational factors were high temperature
(27-40 centigrade), intensive noise (up to 92-98 dBA) at some workplace.
Labor of operators at automatized and mechanized MMA, BA, and MA producing
plants is classified as "light, non-intensive"; labor of most
workers groups at organic polymer glass producing plants is classified
as "middle heavy". These data show that workers at studied plants
as a rule were intermittently exposed to hazardous chemicals mixture in
combination with high temperature and noise at some workplaces. To evaluate
working conditions influence on workers' health, it should taken into consideration
not only chemicals exposure level, but also various biological effects
of the chemicals and degree of their toxicity. Monoethers of MAA are typical
substances with mainly narcotic effect and slight irritant properties.
Ethers of acrylic acid (AA) possess general toxic and irritant properties.
Following regularities were revealed: increasing of absolute toxicity;
decreasing of potential danger and local irritant effect by increasing
of atom number alcohol radicals in AA and MAA monoethers; increasing of
toxicity, irritant and general toxic effect by increasing of saturation
degree in AA ethers as compared with MAA ethers. Established dependencies
of quantitative biological effect on (meth)acrylates chemical structure
let to predict toxicity of newly synthesized acryl compounds and to increase
the reliability of their non-dangerous levels. Gonadotropic and embryotoxic
effects of some (meth)acrylates at high and low doses and concentration
were revealed in experiments on animals [4]. Workplace air MACs for more
than 30 acryl monomers and chemicals used for their synthesis were establised
on the base of toxicological, hygienic and clinical studies data. Atmospheric
air MACs and water MACs for these chemicals were also established [2].
Most of the studied polymers and co-polymers on the base of acryl and
methacryl monomers are considered as "slightly toxic" compounds.
As a rule poly(meth)acrylates dust do not possess fibroplastic effect.
Workplace air MAC = 10 mg/m3 was established for this group of chemicals.
By deepen health condition investigation some functional disturbances
of nerve and cardiovascular systems were revealed in persons worked at
methylacrylate, acryl emulsions and suspension PMMA producing plants. For
the first time chronic occupational intoxication by MMA was revealed in
workers exposed during a long period (6-20 years) to high concentrations
at MMA and organic polymer glass producing shops. The disease clinical
manifestations are combination of vegetative-vascular dystonia, asthenic-neurotic
or asthenic-organic syndrome and vegetative-sensitive polyneuropathy [1,
3]. Occupational dermatoses can be found in workers exposed to MA and other
chemicals by using poly(meth)acrylates.
Disturbances of menses, gestation, delivery were in 1.5-3.3 times higher
in operator-women exposed to MMA, than in contol women (differences were
statistically significant). There were not statistically significant differences
in newborn health conditions, physical and neuropsychic development of
children of women-workers as compared with control group.
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Discussion and Conclusion
Analysis of obtained data provided evidence that the most important
hygienic problem is hazardous chemicals exposure at high concentrations,
especially volatile substances MMA, MA and BA. Found concentrations presented
certain danger to workers' health. Long time exposure to acryl monomers,
especially MMA, at high concentrations can evoke various pathological changes
in human body and lead to chronic occupational diseases.
Integrated approach to solution the problems of occupational medicine
arising at acryl compounds producing lets to establish and elaborate principal
ways for creating more safe working conditions and preventing occupational
diseases in workers exposed to these chemicals. Fulfilment of sanitary
and medico-biological measures promoted to considerable decreasing of hazardous
chemicals concentrations in air, abrupt decreasing of occupational diseases
and reproductive health improvement of women workers.
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References
1. Blagodatin VM, Golova IA, Blagodatkina NK et al. Industrial hygiene
and occupational diseases in the production of organic glass. Gig Tr
Prof Zabol 1970; 14(8):11-4.
2. Blagodatin VM, Smirnova ES, Dorofeeva ED et al. Establishing the
maximum permissible concentration of methyl ester of methacrylic acid in
the air of work area. Gig Tr Prof Zabol 1976; (6):5-8.
3. Sharova TG, Fedotova IV, Dorofeeva ED, Blagodatin VM Development,
course and late sequelae of diseases in workers engaged in organic glass
production. Med Tr Prom Ekol 1993;(9-10):8-10.
4. Smirnova ES, Blagodatin VM Effect of the methyl ester of methacrylic
acid in small concentrations on sexual function of white rats Gig Tr
Prof Zabol 1977; (2):49-51.
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