Hydrocarbon insecticides: their risks for environment and human health

Insecticides are used to control diseases spread by arthropods, but theys vary greatly in toxicity. Toxicity depends on the chemical and physical properties of a substance, and may be defined as the quality of being poisonous or harmful to animals or plants. Poisons have many different modes of action, but in general cause biochemical changes which interfere with normal body functions. Toxicity can be either acute or chronic. Acute toxicity is the ability of a substance to cause harmful effects which develop rapidly following absorption, i.e. a few hours or a day. Chronic toxicity is the ability of a substance to cause adverse health effects resulting from long-term exposure to a substance. There is a great range in the toxicity of insecticides to humans. The relative hazard of an insecticide is dependent upon the toxicity of the pesticide, the dose received and the length of time exposed. A hazard can be defined as a source of danger.The great majority of insecticides are poisonous to man and his beneficial insects and animals and are carcinogenic agents particularly, the halogenated hydrocarbons containing benzene ring

4-Week repeated oral dose toxicity study of 1,4-dichlorobutane in rats / 한국실험동물학회지

The present study investigated the potential subacute toxicity of 1,4-dichlorobutane by a 4-week repeated oral dose in Sprague-Dawley rats. The test article was administered once daily by gavage to male rats at dose levels of 0, 100, 300, and 1,000 mg/kg/day for 4 weeks. All rats were sacrificed at the end of the treatment period. During the test period, clinical signs, mortality, body weight, hematology, serum biochemistry, gross findings, and organ weight were examined. At 1,000 mg/kg/day, an increase in the clinical signs and weights of the liver and kidneys was observed in the male rats. Serum biochemical investigations revealed an increase in alanine aminotransferase, alkaline phosphatase, total cholesterol, total bilirubin, phospholipids, blood urea nitrogen, and gamma glutamyl transferase levels. There were no treatment-related adverse effects in the low and middle-dose groups. In the present experimental conditions, the target organs were determined to be liver and kidney. The no-observed-adverse-effect level was considered to be 300 mg/kg/day in rats.

The Characteristics of the Appearance and Health Risks of Volatile Organic Compounds in Industrial (Pohang, Ulsan) and Non-Industrial (Gyeongju) Areas

OBJECTIVES: The aim of this study was to identify the health and environmental risk factors of air contaminants that influence environmental and respiratory diseases in Gyeongju, Pohang and Ulsan in South Korea, with a focus on volatile organic compounds (VOCs). METHODS: Samples were collected by instantaneous negative pressure by opening the injection valve in the canister at a fixed height of 1 to 1.5 m. The sample that was condensed in -150degrees C was heated to 180degrees C in sample pre-concentration trap using a 6-port switching valve and it was injected to a gas chromatography column. The injection quantity of samples was precisely controlled using an electronic flow controller equipped in the gas chromatography-mass spectrometer. RESULTS: The quantity of the VOC emissions in the industrial area was 1.5 to 2 times higher than that in the non-industrial area. With regards to the aromatic hydrocarbons, toluene was detected at the highest level of 22.01 ppb in Ulsan, and chloroform was the halogenated hydrocarbons with the highest level of 10.19 ppb in Pohang. The emission of toluene was shown to be very important, as it accounted for more than 30% of the total aromatic hydrocarbon concentration. CONCLUSIONS: It was considered that benzene in terms of the cancer-causing grade standard, toluene in terms of the emission quantity, and chloroform and styrene in terms of their grades and emission quantities should be selected for priority measurement substances.

Occupational Diseases in Workers Exposed to Organic Solvents / 한양의대학술지

Organic solvents are hydrocarbon-based substances that dissolve another substance. Organic solvents are usually lipid soluble, volatile and commonly used for painting, printing, degreasing, cleaning, thinning and extraction. Due to their volatility and lipid solubility, organic solvents are easily absorbed across the alveolar-capillary membrane and through the skin. Because organic solvents are lipophilic, they tend to be distributed to lipid-rich tissue, such as adipose tissue, nervous system and liver. Almost all organic solvent can induce skin diseases such as acute irritant dermatitis and chronic eczema. Some organic solvents are associated with allergic contact dermatitis. General and nonspecific central nervous system depression is another common toxic effect induced by most organic solvents. It shows symptoms which are the same as those from alcohol drinking, and those symptoms are completely resolved by removal from exposure to solvents. Long term and repeated exposures to organic solvents can also lead to chronic adverse neurobehavioral effects. These effects are also called as chronic toxic encephalopathy, chronic solvent intoxication and psycho-organic syndrome, and commonly reported symptoms of them are headache, depression, anxiety, and impairment of recent memory. Organic brain lesions can be found in workers suffering from psycho-organic syndrome, and in this case, there is a possibility of persistent disabilities. Carbon disulfide, n-hexane, and methyl n-butyl ketone are specifically toxic to the peripheral nervous system, and cause a symmetric ascending sensory and motor polyneuropathy. Halogenated hydrocarbons including carbon tetrachloride show toxic effects on the heart, liver, kidney, and blood. Toluene can sensitize the heart to arrhythmogenic effects of epinephrine, so sudden death in young and healthy people can be ensued from glue sniffing. Benzene is able to induce any type of leukemia, especially in victims with benzene-associated aplastic anemia. Exposure to some solvents during pregnancy has potential to induce congenital malformation and spontaneous abortion. In the treatment of diseases by organic solvents, the first step should be removal from exposure to the causative solvent.

Comportamiento hemodinámico de pacientes hipertensos crónicos sometidos a anestesia general balanceada comparativo con sevoflurane a isoflurane para cirugía intra abdominal electiva / Hemodynamic patients behavior hipertensos chronic submitted to comparative balanced general anesthesia with sevoflurane to isoflurane for surgery intra abdominal elective

Se realizó un estudio comparativo de Anestesia general balanceada, en el cual los compuestos halogenados de más reciente inclusión en nuestro hospital (Isoflurane y Sevoflurane), en pacientes con Hipertensión arterial crónica, intervenidos quirúrgicamente para cirugia intraabdominal electiva , se comparo el comportamiento hemodmamico durante los diferentes tiempos anestesicos, (Induccian, Intubacion, Incision, Mantenimiento, Extubacion y Recuperación).El estudio comprendio 55 pacientes, distribuidos de la siguiente manera Protocolo 1 ( Isoflurane) n=25, Protocolo 11 (Sevoflurane ) n = 30 En cada grupo se monitorizo la PAS, PAD, FC, desde su mgreso a sala de operaciones, realizandose las mediciones cada 5 mmutos. A todos los pacientes se administró Midazolam a dosis de sedación 0.03 kg en sala de recuperación. Una vez en el quirófano se realizó inducción o Tiopental (5 mg/Kg), Fentanil (5mcg/Kg.), Vecuronio (0.O8mg/Kg),mantenimiento con Fentanil (lmcg/Kg), cada 30 minutos, Vecurnio (0.02 40 minutos, Isollurane o Sevoflurane, según el protocolo que le correspondió. En sala de Recuperación se continuaron tomando los parámetros vitales cada 5 minutos durante 1 hora y se registraron en la hoja de recoleccion de datosuran todo el procedimiento anestésico también se comparan las complciaciones encontradas, siendo las complicaciones más frecuentes para ambos grupos hipertensión arterial, taquicardia, bradicardia e hipotensión. La distribución de los apcientes enc ada protocolo se realizó por un mpetodo aleatorio simple, realizado en la visita pre-anestésica, en la cual cada pacientes escogió de unabolsa un número del 1 al 100, asignándosele a los números impares el protocolo número 1, los pares el protocolo número 2. A partir de los resultados obtenidos podemoa afirmar que ambos compuestos halogenados brindan buena estabilidad hemodinámica en este tipo de pacientes y que la incidencia de complicaciones fueron ligeramente menores con svoflurane auqneu esta diferencia no fue significativa

Halomethane-chlordecone (CD) interactive hepatotoxicity--current concepts on the mechanism.

Why is a low dose of toxic chemical nontoxic? What makes a larger dose of the same chemical toxic? Extensive work done to understand the mechanism of halomethane hepatotoxicity and its potentiation by chlorinated insecticide, chlordecone has resulted in the understanding of these basic tenets of toxicology. Studies suggest that ordinarily a small dose of halomethane causes limited liver injury which is accompanied by stimulated tissue repair enabling complete recovery from injury before manifestation. A large dose of halomethane becomes toxic due to suppressed tissue repair, which permits injury to progress in an unchecked fashion. Exposure to very low levels of chlordecone results in highly exaggerated toxicity of ordinarily nontoxic doses of halomethane because of suppressed hepatocellular regeneration and restoration, permitting the progression of liver injury ultimately resulting in liver failure and animal mortality. This concept is further supported by the observation that, while exposure to even high levels of phenobarbital and subsequent low nontoxic doses of halomethane results in greater level of initial liver injury, tissue repair is not completely suppressed; it is slightly postponed by 24 hr, but then much higher rate of tissue repair ensures and consequently enables the animals to completely recover from liver injury and survive. Thus, whether initiation of tissue repair processes occurs or not is the critical determinant in the ultimate manifestation of hepatotoxicity and its end result of either animal death or recovery and survival. Currently understood 'Mechanisms of toxicity' adequately explain only how toxic injury begins. These mechanisms do not permit us to predict the ultimate outcome of toxicity.(ABSTRACT TRUNCATED AT 250 WORDS)

Cambios psicomotrices secundarios a la exposición de residuos anestésicos inhalados / Psychomotor chnges secundaries to trace inhalated anesthetic exposition

Se aplicó una batería de 5 pruebas para detectar las posibles alteraciones en las funciones psicomotoras en el personal expuesto a residuos anestésicos: A).- Médicos Residentes con menos de dos años de contacto con anestésicos. B).- Médicos con más de dos años de exposición. C).- Un grupo de Médicos no expuestos. Simultáneamente se determinó un muestreo de residuos anestésicos en las áreas de trabajo y en la sangre venosa de los sujetos de los tres grupos. Encontrándose modificaciones psicomotoras de percepción, en el razonamiento abstracto y en las destrezas, pudiéndose correlacionar con las concentraciones de halogenados en sangre venosa y del medio ambiente.

Trihalomethane in the drinking water of Tehran

Natural sources of water contain some halogenated organic compounds after disinfection by chlorine. Trihalomethanes are one group of the chlorination by products that suspected of being carcinogenic inhuman unfortunately, these compounds are in finished water of all treatment plants that use chlorine as a disinfectant. In this study, the concentration of total THMS of water treated in the water treatment plant No.1 of Tehran had been measured by spectrophotometric method, along the month of June, 1371. Results of experiments have shown that organic contents of Tehran drinking water were not considerable in the period of survey. The mean concentration of TTHMS in water samples is estimated to be 28 micrograms per liter and none of the analyzed samples was considered polluted

Cryoextraction of Cataract

In 1910 Scholler introduced the use of low temperatures in the field of ophthalmology. The report of cryoextraction of cataract by Krwawicz in 1961 acted as a catalyst; ophthalmologist all over the world saw the value of the cryosurgery in reducing the number of unintentional capsular ruptures. There are several types of cryogenic instruments. The most commonly used cryogens in ocular surgery are solid carbon dioxide, halogenated hydrocarbons (Freons) and liquid nitrogen. The major advantage of cryoextraction over the forceps and erisophake technics is the reduction of unintentional breakage of the lens capsule with the resulting decrease in the formation of secondary membranous cataracts and in the onset of postoperative inflammations. The applications of cryoextraction on the intumescent cataract, lens witb torn capsule, luxated lens and planned extracapsular method are briefly described.