Hyperaluminemia in renal failure: the influence of age and citrate intake.

Following the occurrence of aluminum encephalopathy in four patients with chronic renal failure, we studied 34 azotemic patients seen during the same year and five volunteers who took varying combinations of aluminum hydroxide and an alkalinizing citrate (Shohl's) solution. We found that the four encephalopathic cases were older than the 34 azotemic patients (68 years +/- 14 SD, vs 50 +/- 13, p less than 0.05), had a higher mean serum aluminum value (727 micrograms/l +/- 320 vs 92 +/- 73, p less than 0.005), had taken more aluminum hydroxide (5 g/day +/- 0.9 vs 1.6 +/- 1.8, p less than 0.01), and more Shohl's solution (64 ml/day +/- 19 vs 20 +/- 29, p less than 0.01). In all 38 patients the serum aluminum values correlated directly with age (p = 0.01), aluminum hydroxide (p = 0.001) and concomitant citrate intake (p = 0.004). In the five healthy volunteers the 24-hour urinary aluminum excretion increased from a baseline of 22 micrograms +/- 19 SD to 167 +/- 109 (p = 0.05) during aluminum hydroxide intake, rising to 580 +/- 267 (p = 0.01) during the simultaneous intake of citrate and aluminum hydroxide. Corresponding serum aluminum values were 11 micrograms/l +/- 2 SD, 44 +/- 34 (p = 0.1), and 98 +/- 58 (p less than 0.05). Thus citrate seems to enhance aluminum absorption and may cause encephalopathy in patients with chronic renal failure, especially the elderly.

Management of patients with multiple chemical sensitivities at occupational health clinics.

The difficult task of managing patients with MCS requires a multidisciplinary effort involving the occupational medicine physician, social worker, occupational therapist, physical therapist, psychologist, vocational rehabilitation specialist, industrial hygienist, and other involved professionals. Important objectives of management include complete review of the history and clinical findings, appropriate choice of diagnostic tests, search for additional exposure information, emphasis of "well" behavior, health education of the patient and prevention of further illness. Because of the chronic nature of MCS and the difficulty many patients have in coping with MCS, pharmacologic and psychologic interventions should be considered. Interaction of the clinic with the patients employer, insurance carrier, or attorney must be carefully planned and communicated only after receiving the patient's informed consent. Patient education should include general principles of toxicology, industrial hygiene measures to reduce hazardous exposures, factors which may aggravate the illness, and resources available to obtain further information and assistance.

Police and corrections.

The author summarizes important occupational hazards of police and corrections work. Included in this chapter are morbidity and mortality data of police officers that describes increased risks of suicide, homicide, and ischemic heart disease. Information on tuberculosis exposure in correctional workers and of bloodborne pathogen exposure in police and corrections work is presented. The discussion concludes with strategies for the prevention of illness and injury among police officers and corrections workers based on these data.

Severe peripheral neuropathy after exposure to monosodium methyl arsonate.

A case of severe peripheral neuropathy after several days of exposure to a pesticide spray containing monosodium methyl arsonate (MSMA) is reported. The clinical manifestations of symmetrical peripheral neuropathy with stocking-glove sensory deficit, decreased position sense, decreased and absent deep tendon reflexes, and muscle wasting are consistent with those described in other cases of arsenic intoxication. The anemia, leukopenia, and bone marrow changes of dyserythropoiesis in this case are also similar to those previously described with arsenic intoxication. The authors discuss the possible contribution of toxicity from exposure to other pesticides.

Ventilatory function after exposure to various respirable hazards in a population of former coal miners.

The ventilatory function of 406 male former coal miners who had presented at the Cook County Hospital occupational medicine clinic between January 1976 and April 1987 was studied to determine whether subsequent exposure to respiratory hazards after leaving the coal mines adversely affected lung function. The miners were divided into five exposure groups based on their exposure to respirable hazards. These were coal dust only, coal dust plus asbestos dust, coal dust plus silica dust, coal dust plus another respirable hazard and coal dust plus two other respirable dust exposures. Duration of employment in coal mines, race, smoking history, and mean age were not significantly different between the various exposure groups. No significant difference was found in the per cent of predicted forced expiratory volume in one second (FEV1), per cent of predicted forced vital capacity (FVC), and FEV1/FVC when the coal dust only group was compared with each of the other four exposure groups using ANOVA. Among former coal miners who present for a respiratory disability determination, therefore, exposure to respirable hazards subsequent to employment in coal mines is not associated with a statistically significant deterioration in ventilatory function.

The fall of zinc protoporphyrin levels in workers treated for chronic lead intoxication.

A temporal fall of zinc protoporphyrin (ZPP) levels in whole blood was observed in 51 patients with occupational chronic lead intoxication who were removed from exposure, treated with intravenous calcium disodium edetate (EDTA), and followed for periods up to 2,273 days. ZPP levels fell, with a mean half-life of 68 days, to a mean baseline level of 36 micrograms/dl of whole blood. The baseline ZPP level was positively associated with the length of exposure (p less than .01) and the blood lead half-life (p less than .001). The amount of EDTA received had no apparent effect on ZPP levels. These data suggest that the fall of ZPP levels is largely a function of red blood cell turnover. The baseline ZPP level appears to be a useful biologic index of the biologically active pool of lead for at least two years after removal from exposure.

Activities of an employer independent Occupational Medicine Clinic, Cook County Hospital, 1979-1981.

In July 1976, Cook County Hospital, a 1,363-bed general public hospital in Chicago, Illinois, established a hospital-funded Occupational Medicine Clinic. A review was made of the clinic records of the 486 new patients evaluated at the clinic from July 1979 to June 1981. Information is presented concerning age, ethnic origin, sex, union representation, referral sources, reason for the referral, number and type of toxic exposure, diagnosis, occupational relationship of the disease, and disposition.

Elimination kinetics of blood lead in workers with chronic lead intoxication.

Blood lead elimination half-lives were determined for 65 patients with occupational chronic lead intoxication who were removed from exposure, treated with intravenous EDTA, and followed for periods of up to 2,419 days. The median overall blood lead elimination half-life was 619 days in patients with normal renal function and 1,907 days in patients with renal impairment. Slow-phase elimination half-lives in patients followed for longer than 5 years ranged from 1,658 to 7,189 days. Blood lead concentrations declined during periods of chelation with a mean half-life of 7 days and rebounded to near prechelation concentrations following termination of chelation with a mean doubling time of 27 days. The overall blood lead elimination half-life was positively associated with length of follow-up (p less than 0.001), age (p = 0.04), and duration of exposure (p = 0.02), but was not associated with the initial blood lead concentration following cessation of exposure or the total amount of EDTA received.