Laboratory investigation of a poisoning epidemic in Sierra Leone.

In June 1986, an epidemic of poisoning occurred in Sierra Leone, West Africa; it involved 49 persons--with 14 deaths. Our laboratory's approach and investigation of this incident is described. Using positive chemical ionization mass spectrometry and nuclear magnetic resonance spectroscopy, the toxicant was identified as parathion, a highly toxic organophosphorus pesticide. Analysis of various items supported the epidemiologic hypothesis that bread was made from contaminated flour and that the flour became contaminated with parathion during a truck shipment. Modern analytical instruments played a major role in this laboratory investigation and effected the identification of the unknown toxicant within hours of receiving the initial bread sample. Close cooperation and clear communication between the epidemiologic and laboratory teams were important in this investigation.

Gas chromatographic and spectral properties of pentafluorobenzyl derivatives of 2,4-dichlorophenoxyacetic acid and phenolic pesticides and metabolites.

Eleven phenols and 2,4-dichlorophenoxyacetic acid, compounds that may be found in body fluids of humans exposed to pesticides, are derivatized with pentafluorobenzyl bromide and characterized by gas chromatography with electron capture detection. These derivatives are further characterized by positive and negative chemical ionization mass spectrometry, nuclear magnetic resonance spectroscopy, and gas chromatography-Fourier transform infrared spectroscopy. Negative chemical ionization mass spectra of all derivatives have an anionic base peak derived from the parent analyte. In the positive mode the nonchlorinated derivatives have base peaks indicative of the analyte, while chlorinated derivatives are cleaved to give the pentafluorobenzyl cation as base peak. The possibility is explored that ortho-substituted phenols might be formed as byproducts in these derivatizations.

Pentachlorophenol measurements in body fluids of people in log homes and workplaces.

Human exposure to pentachlorophenol (PCP) was evaluated in the normal population (controls), residents of PCP-treated log homes, and persons exposed primarily in the workplace. Blood and urine samples were analyzed by gas chromatography after extraction and acetylation. For 34 controls, serum PCP values ranged from 15-75 ppb with a mean of 40 ppb. For 123 residents of log homes, serum levels ranged from 69-1,340 ppb with a mean of 420 ppb. In such homes, serum levels for children were significantly higher than those for parents, averaging 1.8 times greater. Serum and urine values for workers varied widely, depending on the workplace, with serum levels ranging from 26 to 84,900 ppb of PCP. Urinary concentrations when corrected for creatinine values correlated well (r = 0.92) with serum concentrations. Coating PCP-treated logs of home interiors with a sealant reduced serum PCP levels in the residents.

Determination of 19 chlorophenols by packed-column gas chromatography.

The use of packed columns has been explored for the gas chromatographic separation and identification of all 19 chlorophenol congeners after acetylation. Numerous mixtures of polar or nonpolar packings with either of two commercial Bentone 34 mixtures were tested. A mixture of 5% OV-101, 1.75% Bentone 34 on Chrom W-HP (100/120) mixed with twice its weight of 3% OV-225 on 100/120 Supelcoport separated all 19 congeners.

Determining pentachlorophenol in body fluids by gas chromatography after acetylation.

A sensitive, precise, and accurate method for rapidly analyzing body fluids for pentachlorophenol has been developed. The method includes acidification and extraction of the fluid with hexane. The extract is reacted with acetic anhydride, washed with buffer, and injected into a gas chromatograph fitted with an electron capture detector. Quantitation of the pentachlorophenol is based on the ratio of the peak height of pentachlorophenyl acetate to an internal standard, tribromophenyl acetate. The lower detection limit in urine or serum is 1-2 parts per billion. The method was applied to workers in pentachlorophenol formulating plants and to residents of pentachlorophenol treated log houses. Hydrolysis increased the yield of determined urinary pentachlorophenol by a factor of approximately 1.8. Serum levels of pentachlorophenol were 2-3 time higher than the corresponding whole blood levels.

A fatal episode of accidental methomyl poisoning.

Three fatalities from the accidental ingestion of methomyl, a carbamate pesticide, are reported. The methomyl had been stored in an unlabeled tin can and was accidentally used in preparing "roti," an Indian dish. The identification of the source of the poison through animal tests and further chemical identification is described. The lethal dose of methomyl was estimated to have been between 12 and 15 mg/kg body weight.

Acute hemorrhagic cystitis. Industrial exposure to the pesticide chlordimeform.

An outbreak of hematuria occurred from May 20 to May 23, 1975, among employees of a chemical packaging plant. Nine of 22 workers who packaged the insecticide chlordimeform in a separate shed became severely ill with abdominal pain, dysuria, urgency to void, or hematuria. None of 18 persons who worked in other areas of the plant were affected. Four additional workers who had packaged the chemical during the previous year had a history of similar symptoms. Bladder biopsy specimens from three affected persons showed severe hemorrhagic cystitis; chlordimeform and 2-methyl-4-chloroaniline, a metabolite of chlordimeform, were present in urine specimens collected three days after exposure. The illness lasted from one week to two months; the workers recovered completely. Chlordimeform that was injected subcutaneously into three cats produced similar, though less severe, changes in the bladders of two animals.

Fatal parathion poisoning caused by contamination of flour in international commerce.

In January 1976, 79 persons in Jamaica were acutely poisoned by the organophosphorus insecticide parathion. Seventeen died. Cases occurred in three episodes at separate locations, but all patients had consumed wheat flour from a single lot consisting of 5264 cotton bags. Parathion in concentrations of less than 1 to 9900 ppm was identified in flour from six bags in this lot; three had splash marks. The flour had been milled in Western Europe from European wheat, carried in trucks to a dockside warehouse, and loaded aboard ship after 2-5 days' storage. In Jamaica, the flour had moved from quayside to outbreak locations along separate routes through two import houses. Site inspections and review of shipping records suggested that the likely point of contamination was the European port, where foodstuffs and insecticides were stored in the same warehouse.

Histiocytic lymphoma (reticulum-cell sarcoma). Report of five cases.

The subject of lymphomas is discussed and five cases seen in our Oral Surgery Department are Presented. Histiocytic lymphoma, especially of the oral regions, can present with a variety of clinical manifestations. The signs and symptoms, diagnostic modalities, and treatment are discussed and the most recent classification is included.

Epidemiology and pathology of a tetrachlorodibenzodioxin poisoning episode.

We describe epidemiological and laboratory investigation of a poisoning outbreak that involved three riding areas and killed fifty-seven horses, five colts, and numerous other animals. The outbreak was traced to the spraying of the areas with salvage oil contaminated with tetrachlorodibenzodioxin, trichlorophenol, and polychlorinated biphenyls. The contamination of the salvage oil resulted from the improper disposal of toxic industrial waste. In the tissues of the horses available for study, the most prominent lesion was a centrilobular fibrosis of the liver that arose in the wall of the central veins. This lesion resembled the chronic form of veno-occlusive disease of the liver in humans.

Tetrachlorodibenzodioxin: an accidental poisoning episode in horse arenas.

Tetrachlorodibenzodioxin was identified as the apparent cause of an outbreak of poisoning in humans, horses, and other animals. Exposure was related to the spraying of contaminated waste oil on riding arenas for dust control. The contamination resulted from improper disposal of a toxic industrial waste. The pathologic effects and chemical identification of tetrachlorodibenzodioxin are described.