Environmental monitoring in Lithuania. Environmental distress signals: gastrointestinal epithelial barrier after exposure to chemical agents

Lithuania's environment is heavily polluted as a result of domestic and transboundary contamination. The main ecological problems are related to atmospheric pollution; water contamination; soil, water, and forest acidification; nitrogen-compounds overload of soil, water, and food; and contamination with agricultural chemicals and heavy metals. The increased environmental distress is a menace to public health in Lithuania. Experimental studies need to be designed and used to ascertain the effects of environmental distress on the gastrointestinal tract epithelial barrier. Our electronmicroscopic and immunohistochemical study of human gastrointestinal endocrine cells revealed changes in the amount of secretory material and intracytoplasmic vacuolization after exposure to the environmental chemicals such as hexavalent chromium and the herbicide Saprol. The most affected were the EC (serotonin, motilin, substance P), D (somatostatin), A (glucagon), B (insulin), and mast (histamine, serotonin, heparin) cells. These results provide ultrastructural evidence of digestive tract epithelial barrier reaction as an expression of environmental distress signals of the organism.

Recognizing acute health effects of substitute fungicides: are first-aid reports effective?

Recently, many British Columbia sawmills stopped using traditional chlorophenate anti-sapstain fungicides and substituted 2-(thiocyanomethylthio) benzothiazole (TCMTB) and copper-8-quinolinolate (Copper 8). We conducted a cross-sectional study with two aims: to ascertain which acute health effects, if any, were associated with the use of the substitute fungicides; and to determine the effectiveness of first-aid records as a means of detecting acute health outcomes. Workers in five coastal sawmills were asked to complete a self-administered questionnaire about symptoms considered potentially related and unrelated to fungicide exposure, and about injuries commonly reported in sawmills. In addition, we collected first-aid records from the mills, and asked senior workers to estimate the duration of exposure to fungicides for each job. Symptoms found to be consistently elevated in TCMTB mills included dry skin around the eyes, blood-stained mucus from the nose, nose bleed, peeling skin, burning or itching skin, and skin redness or rash. No symptoms were consistently elevated in the Copper 8 mills. Symptoms related to TCMTB exposure were recorded only 12 times in first-aid logs during the study period (versus 335 questionnaire self-reports). This low symptom-recording frequency may be a function of established patterns of first-aid use in which illness symptoms are reported less frequently than injuries.

Mercury and monomethylmercury: present and future concerns

Global atmospheric changes carry the potential to disrupt the normal cycling of mercury and its compounds. Acid rain may increase methylmercury levels in freshwater fish. Global warming and increased ultraviolet radiation may affect the global budget of methylmercury, including its formation and degradation in both biotic and abiotic environments. In this article we review current knowledge on mercury and monomethylmercury with regard to their environmental fate and the potential for human health effects. Recent findings indicate that atmospheric Hg deposition readily accounts for the total mass of Hg in fish, water, and sediment of Little Rock Lake, a representative temperate seepage lake in north-central Wisconsin. It is strikingly evident that modest increases in atmospheric Hg loading could lead directly to elevated levels in the fish stock. It is doubtful, given the experimental limitations in many recent studies, that the temporal pattern for Hg emissions, for background atmospheric Hg concentrations, and for changes in Hg depositional fluxes has been identified. Thus, the present and future questions of whether the environmental impact is of local, regional, or hemispheric significance remain. Contemporary investigations must address these important questions. Human exposure to methylmercury in the United States is probably increasing due to increased consumption of fish and fish products. A recent epidemiological investigation indicates high susceptibility to brain damage during prenatal exposures to Hg. An important objective for future investigation is to establish the lowest effect level for human exposure to methylmercury.

Mercury and monomethylmercury: present and future concerns

Global atmospheric changes carry the potential to disrupt the normal cycling of mercury and its compounds. Acid rain may increase methylmercury levels in freshwater fish. Global warming and increased ultraviolet radiation may affect the global budget of methylmercury, including its formation and degradation in both biotic and abiotic environments. In this article we review current knowledge on mercury and monomethylmercury with regard to their environmental fate and the potential for human health effects. Recent findings indicate that atmospheric Hg deposition readily accounts for the total mass of Hg in fish, water, and sediment of Little Rock Lake, a representative temperate seepage lake in north-central Wisconsin. It is strikingly evident that modest increases in atmospheric Hg loading could lead directly to elevated levels in the fish stock. It is doubtful, given the experimental limitations in many recent studies, that the temporal pattern for Hg emissions, for background atmospheric Hg concentrations, and for changes in Hg depositional fluxes has been identified. Thus, the present and future questions of whether the environmental impact is of local, regional, or hemispheric significance remain. Contemporary investigations must address these important questions. Human exposure to methylmercury in the United States is probably increasing due to increased consumption of fish and fish products. A recent epidemiological investigation indicates high susceptibility to brain damage during prenatal exposures to Hg. An important objective for future investigation is to establish the lowest effect level for human exposure to methylmercury.

[Effect of separate and combined effects of plutonium-239, hexachlorobutadiene and tributyl phosphate on the thymus gland of rats]

It has been established in the experiment on rats exposed to a joint action of plutonium-239, hexachlorobutadiene and ++tributyl phosphate, that manifestations of disturbances from radiation and chemical factors which are more expressed under a joint exposure, are characteristic of the thymus gland damage pattern. As far as lymphocytes count in the organ is concerned, the effect of the joint exposure is no more than additive.

Facial dermatitis caused by chlorothalonil in a paint

A case of acute facial dermatitis caused by staying in a summer cottage is described. Patch testing revealed contact allergy to the paint På Trä Lasur, and to chlorothalonil. Chlorothalonil was used as a pesticide in the paint. Chemical analyses using high-performance liquid chromatography and gas chromatography/mass spectrometry were performed to reveal the purity of the chlorothalonil. Chlorothalonil has earlier been described as a contact allergen, sometimes causing facial dermatitis. The reason for localization to the face has not before been discussed. It is now suggested that it might be due to the high vapour pressure of chlorothalonil. It is concluded that products containing chlorothalonil are unsuitable for indoor use.

A variant of mass (epidemic) psychogenic illness in the agricultural work setting

California experiences episodes of suspected agricultural field worker poisonings annually. These episodes are not only disruptive to ongoing agricultural operations, but the prospect of such poisoning is a source of great concern to workers, employers, and government agencies alike. Three episodes of group illness are examined in which actual poisoning does not seem to be involved. Factors contributing to the generation of these episodes include fear, uncertainty, incomplete understanding of hazards, and social pressures. Physicians can minimize extended disability for workers by reassuring victims and waiting until circumstances are verified before issuing statements which may further alarm or add to already existing fears.

A case-control study of brain gliomas and occupational exposure to chemical carcinogens: the risk to farmers

During 1983 and 1984, 240 newly diagnosed cases of brain glioma and 742 controls (465 non-glioma nervous system tumors and 277 patients with other neurologic diseases) were recruited and interviewed in the neurologic and neurosurgical departments of two hospitals in Milan, Italy. The occupational histories of cases and controls were compared, and relative risk estimates, adjusted for sex, age, residence, and socioeconomic status, were computed using the Mantel-Haenszel method. A statistically significant risk increase was found for farmers (relative risk (RR) = 1.6, p = 0.0025). This risk increase was attributable to those farmers who reported the use of chemicals (insecticides or fungicides, herbicides, and fertilizers). Among the three groups of investigated agrochemicals, only the use of insecticides or fungicides was associated with a significant increase in relative risk (RR = 2.0, p = 0.006). Many farmers exposed to fungicides reported the use of commercial compounds of copper sulfate. Some of these compounds contain methyl urea, which has a specific carcinogenic effect on the nervous system in animals. These data suggest that the occupational exposure of farmers to agrochemicals might be responsible for the observed excess risk of brain glioma in farmers.

An outbreak of contact dermatitis in farm workers

Fourteen of twenty-six migrant workers developed contact dermatitis at a single tomato-strawberry farm in Tennessee. Investigation identified one of eleven pesticides used by the farmer, 2,4-dichloro-6-(o-chloroanilino)-s-triazine anilazine; Dyrene), as the cause of the dermatitis in six of seven workers who were available for patch testing. As a result of this investigation, the label on Dyrene has been revised to warn users of possible sensitization.

Allergic contact dermatitis from 2-n-octyl-4-isothiazolin-3-one, a paint mildewcide

Severe allergic contact dermatitis from a paint mildewcide, 2-n-octyl-4-isothiazolin-3-one, developed in a worker formulating latex paints within a paint manufacturing company, Guinea pig maximization testing demonstrated this to be a moderate sensitizer. Further cases of allergic contact dermatitis may be encountered as the use of this biocide increases in the market place.

Fungicide-induced contact dermatitis

Tetrachloroisophthalonitrile (TCPN) is an agricultural and horticultural fungicide used in many parts of the world. In Northern Europe it is also used as a wood preservative. The substance has well-known toxic properties through skin contact, and has recently been reported as inducing allergic contact dermatitis. We report an epidemic of contact dermatitis in a Norwegian wooden-ware factory, which we attribute to TCPN. 14 out of 20 workers had skin complaints which were work related. Half of these cases were shown to be of allergic origin. The toxic and allergic properties of TCPN render this compound unsuitable for use in the wooden-ware industry. A re-evaluation of its use in agriculture and horticulture seems appropriate.

Circadian rhythms of RNA, DNA and protein content in the rat thyroid, adrenal and testis in chronic pesticide exposure. I. Effects of a fungicide (Mancozeb)

Ninety days of exposure to the fungicide Mancozeb, 100 ppm/day, affects the circadian rhythms of RNA, DNA and proteins in the thyroid and adrenal and slightly but statistically significantly, the testicular RNA content in the rat. The thyroid RNA rhythm shows an almost 12-hour phase advance without change in mesor, but with a decrease in amplitude and in the percent of total variability of RNA in the group, attributable to the circadian rhythm (PR). In the adrenal, the circadian rhythm of RNA and DNA is lost as a group phenomenon and the mesor of the circadian rhythm of protein content is elevated. The testicular RNA rhythm shows multiple peaks, suggesting frequency demultiplication and a loss of the circadian rhythm as a group phenomenon. Chronotoxicology appears to be essential in detecting the adverse effects of pesticides.

Dermatitis from slimicides in a paper mill

Dermatitis is reported from slimicides added to wood pulp slurry in a paper mill. The active constituents of the slimicides involved were bis-1,4-bromoacetoxy-2-butene and 2,3-dichloro-4-bromotetrahydrothiophene-1,1-dioxide. Wood pulp slimicides include many chemicals which are highly irritant and potentially sensitizing to the skin.

On-line storage and retrieval of chemical information. II. Substructure and biological activity searching

An improved interactive system for searching substructure and biological activity data has been developed. Features of the system include a two-level substructure search (fragment screen and atom by atom) and an expanded biological activity data base. The system operates on a file of about 150 000 compounds.

Neurotoxicity and behavioral effects of thiram in rats

Eight of 24 female rats fed 66.9 mg/kg-day of thiram developed neurotoxicity. The neurotoxic effects were characterized by ataxia and paralysis of the hind legs. There were demyelination, degeneration of the axis cylinders, and presence of macrophages in the nerve bundle of the sciatic nerve. Degeneration in the ventral horn of the lower lumbar region of the spinal cord was evidenced by chromatolysis of motorneurons, pyknosis, and satellitosis. During a second experiment, 4 of 24 females fed 65.8 mg/kg--day also developed ataxia and paralysis. An additional 9 females showed clasping of the hind feet when picked up by the tail. Nerve conduction could not be measured for one severely ataxic rat and the electromyogram indicated a loss of motor unit function. Histopathology of this rat, along with the others, suggests the peripheral nerve as the primary site of the lesion. Thiram also caused behavioral changes in apparently normal rats. The walking pattern of the hind legs was altered with decreases in stride width and the angle between contralateral steps. These rats required significantly more shock-motivations and cleared a lower height in a jump/climb ability test. An open-field study indicated that thiram caused hyperactivity in the nonataxic rats of both sexes. Three of 24 rats fed 95.8 mg/kg-day of ferbam also developed ataxia or paralysis.

Allergic dermatitis from a new pesticide

In four patients suffering from allergic contact eczema, the risk of sensitization to a new residue-leaving fungicide (Plondrel) used in spraying roses is considered. Two patients, however, were probably also sensitized to materials from the roses themselves. By gas-liquid chromatography the amount of the fungicide, especially in the leaves of roses, appeared to be rather high. The role of pesticides has to be considered when sensitizing agents of plant dermatitis are investigated.

The effects of 1, 2, 3, 4, 10, 10-hexachloro-1, 4, 4a, 5, 8, 8a-hexahydroxy endo, exo-5, 8-dimethionaphthalene (aldrin) and sodium ethylenebisdithiocarbomate (nabam) on the chick

Fertile White Leghorn chicken eggs were injected on the tenth day of incubation with either 0, 10, 20, 30, 40 or 50 p.p.m. Aldrin or 0, 5, 10 or 15 p.p.m. Nabam and allowed to hatch. Aldrin neither did induce any deformities nor had any effect on hatchability, thyroid weight and histology. However, within three days after hatching, there was greater mortality in chicks treated with higher concentrations of the pesticide. Aldrin at higher concentrations significantly reduced 125I uptake by the thyroids. This was evident in the iodine fractions after chromatographic separation of the thyroid extracts. Nabam not only reduced hatchability but also induced deformities in the higher concentration groups. The thyroids showed an increase of resorption vacuoles in the colloid. Even though the thyroid weights increased in all experimental groups, a significant increase in 125I uptake was seen only in the 15 p.p.m. injected animals. This group also showed a reduction in radioactivity of thyroxine fraction but an increase of 125I in tyrosines. The significance of these results are discussed.