Fluoride Levels in Principal Foodstuffs (Dried Corn, Capsicum) in a Fluoride-Contaminated Area in the Province of Sichuan, China, and Their Chemical Properties / 日本農村医学会雑誌

The incidence of fluorosis, believed to arise from the burning of coal, has been frequently reported in the highlands in the southern part of China. With a lot of rain and a climate of low temperature, the hilly region produces coal and inhabitants use it as a fuel for cooking and heating. The fossil fuel used by them is mostly powdery. It is mixed with dirt and rolled up into bolls. In that way,the people make the briquettes that burn a long time.Ordinary houses have no chimneys to belch forth smoke, so that it stagnates indoors for a while. Soot and smoke, before flowing out via the openings in the roof shingle of the loft, spoils farm produce stored there. Because the smoke contains high concentrations of fluoride derived from coal and dirt, it is believed that eating farm produce exposed to the smoke is one of the major factors for fluoride poisoning. Many researchers have thus far analyzed farm products for fluoride content and confirmed that high levels of fluoride were contained in their samples.In the present study, we measured fluoride concentrations in some samples of corn and capsicum produced in a rural area of Sichuan, China on one hand and on the other examined the water-solubility of fluoride. Furthermore, screening tests for chronic endemic dental fluorosis were performed on students to survey the fluoride contamination in the past as compared with the present state.Incidentally, indoor air-borne fluoride concentrations in this area averaged out at0.047mg F/m3 (15 times as high as the mean in a community that was free of fluoride contamination). The fluoride content of the drinking water from a spring in the nearby hill, measured with use of a fluoride-specific electrode method,was within the range from 0.2 to 0.3μg/ml.

Nationwide Survey of Clinical Cases of Pesticide Poisoning/Disorders in Japan, 2001-03 / 日本農村医学会雑誌

Data concerning clinical cases of pesticide poisoning/disorders were collected from members of the Japanese Association of Rural Medicine during 2001-2003, and were analyzed statistically.A total of 194 cases of poisoning/disorders by pesticide exposure were reported from 36 hospitals and other medical institutions. Suicide cases accounted for 74% of the total number of cases, which was followed by the cases caused by exposure during spraying (17%) and drinking/eating by mistake (7%).In 144 suicide cases, those of males accounted for 52%, the middle-aged and older people constituted the majority. By types of clinical manifestations, almost all of the cases were acute or subacute pesticide poisoning (98%). Organophosphate insecticides were the most frequent inducers of the cases (39%), which was followed by bipyridylium herbicides (23%). When it comes to the outcome, more than 80% of suicide cases with paraquat products resulted in death.There were 39 cases of pesticide poisoning/disorders resulting from exposure during spraying, preparation or settling, and working in sprayed area. In these cases, males accounted for 70% the middle-aged and older people made up the majority. By types of clinical manifestations, the cases of acute or subacute pesticide poisoning accounted for 39%, which was followed by acute dermatitis (33%), chemical burn (14%), and ocular disorders (11%). The pesticides that induced clinical cases varied greatly. Main factors contributing to the onset of pesticide poisoning/disorders were insufficient protective clothing (44%), self conceit (19%), insufficient information (14%), and carelessness (12%).

Research on Prevention of Pesticide Poisoning in Asia : A Review / 日本農村医学会雑誌

In japan, pesticides have been used increasingly after World War II and pesticide poisoning has been a major issue of rural medicine. In other Asian countries, pesticide poisoning also seems to be a great concern of rural medicine and occupational and environmental medicine as well. We reviewed the results of research on the prevention of pesticide poisoning in Asia with the reports of international organizations and articles which appeared in medical journals.The WHO Glabal Information Network on Chemicals worked out an international protocol to collect and analyze the cases of pesticide poisoning, and is carrying out hospital-based surveys in east and south Asia from 1998. These data were discussed in comparison with the results of our hospital-based survey of pesticide poisoning in 1998-2000.Also, FAO has been exploring the concept of “community integrated pest management (CIPM)” from 1999, in Asian countries. In a project related to this, farmers were asked to report their pesticide use and symptoms, and researchers analyzed the data and gave advice to the farmers, and these practices produced so fruitful findings that the farmers have come to refrain from using hazardous pesticides of their own accord. These research projects are expected to complementarily contribute to the prevention of pesticide poisoning. We resumed the hospital-based survey of pesticide poisoning in 1996, and have collected and analyzed several hundreds cases. In order to reduce pesticide poisoning in Japan and other Asian countries, we are interested in rendering cooperation in those projects.

A Clinical, Epidemiological Study on Chronic Neurological and Psychiatric Disorders Caused by Pesticides / 日本農村医学会雑誌

Pesticide poisoning is one of the most inportant health issues associated with rural medicine, and chronic nervous and mental disorders are its importnat sequelae. We investigated suquela cases nationwide, and reviewed chronic nervous and mental disorders from a clinical and epidemiological point of view.<BR>Our nationwide survey found one reported case of delayed neuropathy. The patient ingested organophosphorus insecticides, and showed delayed neuropathy dozens days after.<BR>Cases of delayed neuropathy attributable to Mipafox was reported in1951.This disease is mainly caused by organophosphorus insecticides. Carbamate insecticides are also known as the agents to induce delayed neuropathy. Herbicide Glufosinate (Basta<SUP>TM</SUP>) was put on the market in 1984. The case reports published during the 1990's pointed out that some Glufosinate poisonings cause amnesia and disorientation. Thesecases were reviewed according to the types of pesticides or their groups.<BR>An epidemiological investigation of neurological and psychiatric desorders among such workers exposed to several types of pesticides as plantation workers and sheep dippers was made. These exposed workers were at high risk of mild cognitive dysfunction, tremor, weakness, and so on to a significant extent. Those children who were exposed to organochlorine insecticide and pollutant via placenta or milk were also surveyed whether they had impairments of nervous and mental development. Highly exposed children were significantly slow in development relative to their peers. The results of these investigations were also reviewed.

Nationwide Survey of Clinical Cases of Pesticide Poisoning (Disorders) in Japan, 1998-2000 FY / 日本農村医学会雑誌

Data concerning clinical cases of pesticide-induced disorders were collected from members of the Japanese Association of Rural Medicine during 1998-2000 FY throughout the nation, and were analyzed statistically.<BR>1) A total of 209 cases of poisoning by agricultural chemicals were reported from 49 hospitals and other medical institutions.<BR>2) By types of clinical manifestations, the majority of the cases were acute or subacute pesticide poisoning (91%), which was followed by acute dermatitis (5%) and chemical burn (3%).<BR>3) Suicide accounted for 67% of the pesticide poisoning cases, which was followed by accidental exposure on the job during spraying (17%), and so forth.<BR>4) Organophosphate insecticides were the most frequent inducers of the clinical cases (34%), which was followed by bipyridylium herbicides (21%) and a carbamate insecticides (9%), and so forth.<BR>5) There were 43 cases of intoxication during spraying, during preparation or settling, and working in sprayed areas By types of clinical manifestations, the majority of the cases were acute or subacute pesticide poisoning (56%), which was followed by acute dermatitis (23%) and chemical burn (16%).<BR>6) Agricultural chemical compounds responsible for the clinical cases varied greatly. They induced organophosphate insecticides (19%), and bipyridylium herbicides (12%).<BR>7) Main factors contributing to the onset of pesticide-related disorders were insufficient protective clothing (32%), carelessness (22%), and inevitable consequences of pesticide use (10%).

Research on Fluoride Pollution and Fluorosis in Rural Areas of China / 日本農村医学会雑誌

A China-Japan joint project was carried out to study the incidence of fluorosis caused by coal burning in China from 1995 to 1997.<BR>The health survey covered a control area and two flourosis areas. In those research areas, drinking water was not polluted with fluorides. The survey was designed to analyze the health status of people exposed to fluorides and evaluate the relationships between the dose and incidence of fluorosis. The concentration of airborne pollutants in both indoor and outdoor air was measured. The concentration of fluoride in the urine was analyzed and definite diagnoses for dental fluorosis and skeletal fluorosis were determined.<BR>As a result, the incidence of coal burning fluorosis was confirmed in studied areas. Moreover, the fluorosis was caused not only by the direct inhalation of the airbone fluorides in indoor air but also by the intake of cereals polluted with fluorides. Fluoride was contained in both coal and soil. Therefore the mixture of coal and soil used for the adjustment of fire energy contributed to the air pollution to a great extent. The typical polluted crops were red pepper, corn and potato. An extremely high concentration of fluoride in the urine of residents in the polluted areas was detected.

Chronic toxic ellects of herbicide paraquat on rats / 日本農村医学会雑誌

Paraquat is one the most popular herbicides in agriculture in Japan. To study the chronic toxicological effects of paraquat on animals, rats were fed a paraquat-containing diet for 1 year and 2 months (1, 5, 25mg/kg of body weight/day). Paraquat administration induced serious histochemical changes in various organs, such as the lung, heart, kidney and liver in rast. Pulmonary fibrosis occurred in the group of rats given 1mg paraquat/kg of body weight/day in diet.<BR>The alkaline phosphatase activity and creatinine content in the blood serum significantly increased. The concentrations of cholesterol, triglyceride and phospholipid in the serum decreased significantly.<BR>A significant increase of lipid peroxidation was observed in the brain, kidney and liver.

Lipid peroxidative damage and inhalation toxicity by suspended particulate pesticide / 日本農村医学会雑誌

High concentration of airborne particles was detected in greenhouse air after suspended particulate pesticide spraying. The reduction of aerial concentration of resprirable particulate pesticide was relatively slow.<BR>To study the potential health effects of inhaled pesticide, the animals were exposed to the pesticide, methidathion particles in the inhalation exposure chamber. The exposed pesticide particles were approximately 2.16 μm mass median diameter.<BR>The animals exposed to suspended particulate pesticide had a considerable amount of particles within alveolar macropharges and alveolar epithelia. The serious lesion of alveolar epithelia and capillary endothelia of the animals occured after inhalation of methidathion particles.<BR>The vacuolar degeneration of hepatic cell was also cytosol decreased significantly after inhalation of methidathione particles.<BR>The exposure to suspended particulate methidathion induced production of thiobarbituric acid reacting substances (TBARS) in hepatic cells of the exposed animals. The induction of TBARS formation in hepatic cells was remarkable at early period of exposure.<BR>The change of serum transaminase (GOT) activities after exposure to methidathion particle was remarkable. GOT activities also markedly increased at early period of exposure.

Inhalation toxicity of suspended particulate pesticide-supracide FD / 日本農村医学会雑誌

To study the potential health effects of suspended particulate pesticide-Supracide FD, the animals were exposed to the pesticide particle in the inhalation exposure chamber. The suspended particulate pesticide was approximately 2.16μm mass median diameter.<BR>The animals exposed to suspended particulate pesticide had a considerable amount of particles throughout the alveolar region.The particles deposited mainly within alveolar macropharge and alveolar epithelium. The epithelial lesion of the pulmonary tissue and the vacuolar degeneration of hepatic cell of the animals occured after inhalation of pesticide particle.<BR>The exposure to Supracide FD induced production of more thiobarbituric acid reacting substances (TBARS) in comparison to the controls. The change of serum GOT and LDH activities after exposure to pesticide particle was also remarkable. The exposure to the pesticide particle caused no significant effect on the serum cholinesterase activity.

Survey of Content of Nitrate in Well Water of Rural Areas / 日本農村医学会雑誌

We investigated the content of NO<SUB>3</SUB>-N in the well water of the eastern, middle and nothern districts of Nagano Prefecture. The NO<SUB>3</SUB>-N content seasonally changes and takes on the pattern of a high in summer and a low in winter.<BR>Rain is considered to dilute the contaminated well water, but it lets NO<SUB>3</SUB>-N flow from the soil into the.well water, when the rain is poured by a typhoon. As a result, a high content of NO<SUB>3</SUB>-N is measured in the well water.<BR>The water sample of 25 out of 85 wells in Matsukawa Town exceeded the tolerance level of NO<SUB>3</SUB>-N (10 ppm, but 44.3 ppm in terms of NO<SUB>3</SUB><SUP>-</SUP>).<BR>By crop area, the amount of NO<SUB>3</SUB>-N was highest in the fruitgrowing area, which was followed in order of the vegetable-growing area, the flower-growing and the rice planting area.<BR>We consider that the contamination of well water is caused both by chemical fertilizers and the less absorbility of the soil.

Delayed Neuro-Toxicity of Organophosphorous Agents As Demonstrated by Use of Hens / 日本農村医学会雑誌

To demonstrate delayed neuro-toxicity of organophosphate, we administered 13 types of organophosphorous pesticide to hens. Initially, a screening test was performed with nine varieties of the chemical product. Later, four types were given to the fowls. Those hens dosed with S-Seven and Surecide developed ataxia and other neurophatic symptoms in the lower limbs.<BR>After 50 days of observation, all the hens were killed and anatomized. Phathohistological examination revealed various changes in the hens that developed neuropathic symptoms: atrophy, diminution and disappearance of nerve cells in the anterior horn of the spinal cord ; edematous changes in the myelin; swelling of the neuroglia ; atrophy and vaculolar degeneration of liver cells; and necrobiosis of <I>nepaticlobures</I>.<BR>It was found that these changes are closely related with the development of ataxia and doses of the chemical.<BR>It was also found that the pathotistological changes occurred to a less extent in those hens which did not develop toxicoses.

Chronic Intoxication Experimentally Induced by Small Doses of Sumithion-an Organophosphorous Insecticide / 日本農村医学会雑誌

Over the past eight years, small doses of an organophosphorous insecticide known in Japan as Sumithion (fenitrothion) have been administered weekly to rehsus monkeys and beagles. In this report, the results obtained during the past three years are discussed.<BR>During the period, two monkeys and one hound died. Pathohistological examination revealed degeneration and disappearance-regeneration of liver tissues, edema of oculomotor muscle stomas, spinal cords and oculomotorius nerve fibers, and atrophy of limph nodes. These are considered the effects of the insecticide.<BR>The surviving animals did not develop any abnormal changes or signs associated with Sumithion-induced disorders. Weight loss was not observed. Routine blood tests were negative. However, serum chemical analyses conducted in the seventh year showed that there are statistically significant differences in GPT, LDH and cholinestrase activity among the animals.

A Study on Organochlorine Residues in Human Bodies / 日本農村医学会雑誌

Two hundred and thirty adipose tissues were collected from inpatients, who had undergone an operation and an autopsy in the Saku Central Hospital from 1980 to 1982. Organochlorine pesticides were extracted from the adipose tissues and determined by gas-liquid chromatography with an electron-capture detector.<BR>The mean value was 1, 429 ppm for total BHC among males, and 1.665 ppm among females, 4.893 ppm and 3.791 ppm for total DDT, 1.082 ppm and 0.782 ppm for PCB, respectively. Regression analysis between the total BHC residue and the ages of patients indicated a positive correlation for both sexs. As for the relation between the rate of obesity and the residues, low rates of obesity (-10%--19%) were most significantly correlated with high values of total BHC, total DDT and PCB.<BR>We also discussed relations between cancerous diseases and the residues.