Acetic aldehyde and formaldehyde in cutting fluids and their relation to irritant symptoms.

The objective was to study the formation of acetic aldehyde in cutting fluids and its relation to irritation of mucous membranes and the skin. Acetic aldehyde and formaldehyde were analysed in two large cutting fluid systems in an engineering industry. Samples were taken 1-5 times a week during a year. Concentration of the cutting fluid, leakage oils, pH, bacteria, yeast and fungi were analysed weekly. The occurrence of mucous membrane irritation was registered through questionnaires to the exposed workers. About 50 persons were exposed to each of the cutting fluids. The concentration of the aldehydes varied with time and between the cutting fluids. None of the analysed parameters could explain the variable concentration of aldehydes. Mucous membrane irritation was much more common in one of the systems, e.g. the prevalence of irritation in the nose was about 30-40% in workers exposed to a cutting fluid, while the corresponding prevalence was less than 10% in workers exposed to another fluid. The occurrence of symptoms was slightly associated with the concentration of aldehydes and pH of the fluid varied more in the fluid that caused most symptoms. A few measurements of ammonia indicated a higher concentration of ammonia in the fluid that caused most symptoms. It is concluded that irritation of mucous membranes and the skin may vary considerably between different cutting fluids of similar composition and use but the causal factor could not be determined in this study, but a variable pH and an increased concentration of ammonia may be indicators in this context. The concentration of acetic aldehyde vary with time and between cutting fluids with similar composition. A high variability may be an indicator of less stable cutting fluids. Better markers for the surveillance of cutting fluids needs to be developed as well as a health control programme.

Subclass distribution of IgG and IgA antibody response to Pseudomonas pseudoalcaligenes in humans exposed to infected metal-working fluid.

The subclass distribution of the IgG and IgA antibody response in serum was studied in humans exposed to aerosolized metal-working fluid containing Pseudomonas pseudoalcaligenes. This species was consistently found in concentrations of 10(8) bacteria per milliliter of metal-working fluid during 1 year of observation. No increased frequency of respiratory infections or discomfort was related to the exposure to the infected fluid. The antibody response to the bacterium consisted predominantly of IgG1 and IgG2 antibodies. IgG2 antibodies dominated the antibody response to the lipopolysaccharide of the bacterium. IgA1 and IgA2 antibodies were also found. Smokers had significantly reduced antibody levels of all subclasses compared with nonsmokers. The antibody levels in smokers did not differ from levels of the unexposed control group. Analyses of the total serum immunoglobulin concentrations with respect to subclasses revealed that the total IgG2 levels were also significantly reduced in smokers. In nonsmokers, the age of the individuals influenced the antibody levels of the IgG1, IgG2, IgA1, and IgA2 subclasses, the levels decreasing with increasing age. For smokers, the correlation between age and antibody levels was only obvious for IgG2 antibodies. Decreased IgG2 antibody levels in the smokers were also accompanied by decreased FEV1 values (p less than 0.01). Subclass analysis of the antibody response to P. pseudoalcaligenes demonstrated that the subclass pattern for the whole bacterium differed from the pattern of the major cell wall component, the lipopolysaccharide. The significance of qualitative and quantitative differences in the subclass antibody response is discussed.

Serum antibodies to Pseudomonas pseudoalcaligenes in metal workers exposed to infected metal-working fluids.

Metal workers exposed to aerosol from metal-working fluid were examined with respect to serum antibody to the lipopolysaccharide (LPS) of Pseudomonas pseudoalcaligenes. During 1 year of observation this species grew at high concentrations in the fluid (approximately 10(8) CFU/ml), and the air surrounding the metal-working machines sometimes contained more than 10(5) CFU/m3. The levels of antibody belonging to the IgG and IgA classes were significantly higher than in blood donors and in workers newly employed. Comparison with employees not working in the machine hall showed a significantly higher IgG, but not IgA, antibody level. For IgM antibody no such difference was found. Among the exposed workers, non-smokers had significantly higher IgG antibody levels than smokers, whereas no such difference was established for IgA and IgM antibodies. In smokers the IgG antibody level seemed to decline in the long-range time, since there was a negative correlation between the time of employment with exposure to metal-working fluids and IgG antibody level. The antibody data indirectly demonstrate that P. pseudoalcaligenes grown in metal-working fluid penetrated the body surface of metal workers to yield an immune response most probably after inhalation of aerosol containing bacteria. In the metal workers this long-term exposure did not lead to any acute or chronic respiratory discomfort.

Mortality and cancer morbidity in workers exposed to cutting fluids.

This cohort study includes 792 men exposed to cutting fluids that contain mineral oils and additives in a machining industry. Their cancer mortality and morbidity was compared with that of the general population of the same city. The total mortality was not found to be increased, and there were no increased incidences of lung cancer or death resulting from nonmalignant respiratory diseases. Seven of the turners but none of the grinders had squamous cell carcinomas on the skin of the scrotum. There was no increased incidence of cancer of the urinary bladder.

Exposure to triarylphosphate and polyneuropathy: a case report.

This report describes a case of polyneuropathy in a 48-year-old mechanic who was heavily exposed to hydraulic fluids containing isopropylated triphenylphosphate (ITP). A cross-sectional examination of eight other men exposed to hydraulic fluids and eight controls showed differences in EMGs but not in nerve conduction velocities or other values measured in a clinical examination. The study indicates a possible association between heavy occupational exposure to hydraulic fluids and ITP and polyneuropathy.

Exposure to cutting oils and its relation to skin tumors and premalignant skin lesions on the hands and forearms.

In a cohort study the incidence of skin tumors on the hands and forearms of 682 turners exposed to cutting oils was compared to the incidence of the general male population and of office workers. Among the 682 turners, five premalignant squamous cell tumors and eight keratoacanthomas were found between 1960 and 1980. Five of this total of 13 turners with primary skin tumors had another skin tumor as well. Among the 682 men there were four cases of scrotal cancer. Among the 375 office workers examined, no malignant or premalignant tumors or keratoacanthomas were found on the hands or forearms. No primary skin tumors were found among the turners after 1975, when the acid-refined mineral oils were replaced by solvent-refined oils containing a far lower concentration of polyaromatic hydrocarbons, which are probably the cancerogenic agent in the oils. The study shows a greatly increased risk of skin tumors on the hands and forearms of workers exposed to acid-refined mineral oils. Individual susceptibility also seems to be indicated.

Respiratory symptoms and lung function in oil mist-exposed workers.

The prevalence of respiratory symptoms was registered and ventilatory function was determined in 164 men exposed to oil mist. The average exposure time was 16.2 years. One hundred fifty-nine office workers served as controls. The exposed men reported more respiratory symptoms: 14% of the exposed nonsmokers v. 2% of the non-smoking controls having cough at least three months a year. There were no significant differences between spirometric measurements and chest roentgenograms of the men exposed to oil mist and those of the office workers. The lung function of 25 nonsmoking exposed men was further examined with other lung function tests. The mean values for closing volume, slope of the alveolar plateau, total lung capacity, residual volume, elastic recoil at various lung volumes, and diffusion capacity did not differ significantly.

A double-blind comparison of spironolactone and hydrochlorothiazide in hypertensive patients treated with metoprolol.

The antihypertensive effects of hydrochlorothiazide and spironolactone when added to treatment with metoprolol were compared in a double-blind trial comprising 55 previously untreated patients with essential hypertension. Twenty-four patients became normotensive on metoprolol alone, whereas ten patients were randomized to additional therapy with hydrochlorothiazide and ten to spironolactone. Eleven patients dropped out of the trial. Spironolactone was significantly more effective than hydrochlorothiazide as regards reduction of the diastolic blood pressure, Side effects were few and mild during all phases of the study.

A cohort study on cancer among workers exposed to an antirust oil.

An epidemiologic study in an engineering company was prompted by the observation of three cases of cancer; it revealed several more cancers among women who wrapped bearing rings covered with antirust oil, i.e., 12 cases vs 3.9 expected. The 12 tumors were situated in different organs, including the uterus, ovaries, breast, thyroid, brain, colon, and bladder. No known carcinogenic substance was found that could explain the increased incidence of cancer. If the increased incidence is not a random phenomenon, N-phenyl-1-naphthylamine or its nitroso derivative is likely to be the causative agent.