6.Applicability of thresholds of toxicological concern in the chronic dietary risk assessment of transformation products of pesticide active substance.
Hai-xia SUI ; Zhao-ping LIU ; Lei ZHANG
Chinese Journal of Preventive Medicine 2013;47(6):569-572
OBJECTIVETo establish the threshold of toxicological concern(TTC) approach and to apply it in the risk assessment of metabolites, degradation and reaction products of pirimicarb.
METHODSTTC decision tree approach based on Cramer classification was established and Lazar software was used to predict the genotoxicity of the seven transformation products of pirimicarb, namely, R34836, R34885, R35140, R31805, R34865, R16210 and R16192. Dietary exposure in general population as well as in six age population groups was estimated by using data from the Chinese National Nutrition and Health Survey and pirimicarb residue data from national chemical surveillance data in 2011. TTC decision tree approach was used for risk assessment and the exposure was compared with the corresponding TTC values.
RESULTSOf the seven transformations of pirimicarb active substance, namely, R34836, R34885, R35140, R31805, R34865, R16210 and R16192, the maximum dietary exposure of mean and large portion(P 97.5) were all belong to 2-6 age group. The mean exposures of the seven transformation products for 2-6 age group,were 0.0290, 0.0207, 0.0015, 0.0320, 0.0005, 0.6918 and 0.1274 µg/kg,respectively, and the corresponding P 97.5 exposures were 0.0817,0.0581,0.0042,0.0900,0.0014, 1.9459 and 0.3585 µg/kg. Besides, the mean and P 97.5 exposure of R16210 for 2-6 age group was the largest,which were 0.6918 and 1.9459 µg/kg, accounting for 46.12% and 129.73% of the TTC threshold,respectively.
CONCLUSIONTTC decision tree approach is a useful tool for prior screening and primary risk assessment of the transformation products of pesticide active substance.
Carbamates ; toxicity ; Food Contamination ; Humans ; Maximum Allowable Concentration ; Pesticide Residues ; toxicity ; Pesticides ; toxicity ; Pyrimidines ; toxicity ; Risk Assessment
9.Study on the Impurities in Anesthetic Diethyl Ether .
Korean Journal of Anesthesiology 1973;6(2):171-184
The impurities of diethyl ether are mainly acetic aldehyde and ether peroxide. Other impurities are sulfuric acid, sulphur dioxide, mercaptane and ethyl ester. It was believed that these impurities are produced during production and storage. When we use ether containing impurities, inhalation of excessive peroxide can cause salivation, profuse bronchial secretion, lung edema and pneumonia. Excessive aldehyde also irritates the mucous membrane and can cause lacrimation, photophobia, conjunctivitis, an oppressive feeling of the chest, severe cough, headache, unconsciousness, bronchitis and pneumonia. It is well known that the deterioration of ether is favoured by contact with air, heat and sunlight. There are two opposite opinions on reuse of ether. Baskerville(1910) claimed that it should not be used for anesthesia twenty-four hours after the container is opened. However Harry and David Gold(1934) showed that, in ordinary anesthetic ether cans which were opened many times and stoppered with cork, the contents remaining pure by very delicate chemical tests for the usual impurities, aldehyde and peroxide, during a period of months. In order to measure the impurities of ether, four brands of ether for anesthesia were randomly selected for analysis. Type of containers and date of production in each group are as follows: Group I: Kong Shin Pharmaceutical Co. LTD., so called Korean made ether, 140 ml in brown, bottle one month old. Group II: May & Baker LTD., made in England, 100g(140 ml)can. Group III: Mallinckrodt Chemical Works, made in U.S.A., (1/4)lb(113.4 gm) can. Group IV: Showa Co., so called Japan made ether, 160 ml in brown bottle, fourteen months old in three samples and four years and six months old in another three samples, They were analysed by chemical tests for peroxide, aldehyde and acetic acid just after the containers were opened(zero day) and one, two, four, six and eight days later. Ethyl alcohol was analysed by gas chromatography. The results were as follows; Ether peroxide: Threshold limit value for U.S.P. is 7. 1 microgram/10 ml ether (0.025 mg of hydrogen peroxide/25 gm ether), In group I and III, they were within this value from zero to eight days but in group II and IV, they exceed this value already on zero day. Aldehyde: Threshold limit value in U.S.P. is 0.007mg/20ml ether(formaldehyde 0.0005%). In group I, there was nothing on zero day but after twenty-four hours it exceed threshold limit value and increased day by day up to eight days. In groups II, III and IV, they exceeded this value already on zero day, and increased day by day up to eight days but were below maximum allowable concentration for U.S.P. Acidity: The incidence was slightly increased day by day up to eight days but all were within normal range. By gas chromatography, analysis showed 4% ethyl alcohol in group III and IV. On the other hand, to ascertain the interrelationship between the production of impurities and the existence of alcohol or H2O2 in ether, 3% alcohol(group A), 6% alcohol(group B), H2O2 (600 microgramg%)(group C), and H2O2 with 3% alcohol together(group D) were added to ether respectively. In four groups, immediately after one, two, four, six and eight days after the containers were opened, they were analysed for peroxide, aldehyde and acidity. Peroxide: This was increased in all groups just after adding, and increased furthur day by day up to eight days when the increase was marked. Especially in group D, it increased sharply. Aldehycte: It was increased in all groups just after acding, and there after increased or decreased irregularly day by day up to eight days by which time it had increased markedly. Acidity: It was increased in all groups up to one and/or two days, there after decreased day by day up to eight days. However none of the groups exceeded the threshold limit value of 0.4 ml of N/50 NaOH. It was concluded that: 1. Impurities in ether for anesthesia are influenced by type of container for storage, date of its production, and duration after container is opened. 2. Ether for anesthesia should not be used for this purpose, if the original container has been opened longer than twenty four hours. 3. The production of impurities in ether was influenced by the presence of alcohol in ether. 4. It would be better to analyse the ether for impurities by chemical tests prior to clinical use.
Acetic Acid
;
Anesthesia
;
Bronchitis
;
Chromatography, Gas
;
Conjunctivitis
;
Cough
;
Edema
;
England
;
Ethanol
;
Ether*
;
Hand
;
Headache
;
Hot Temperature
;
Hydrogen
;
Incidence
;
Inhalation
;
Japan
;
Lung
;
Maximum Allowable Concentration
;
Mucous Membrane
;
Photophobia
;
Pneumonia
;
Reference Values
;
Salivation
;
Sulfur
;
Sunlight
;
Thorax
;
Unconsciousness
10.Effects of carbon disulfide on blood pressure and electrocardiogram for workers exposed to levels below the national maximum allowable concentration.
Jia CHEN ; Yong-Jun LI ; Wen-Ping YANG
Chinese Journal of Industrial Hygiene and Occupational Diseases 2009;27(11):644-648
OBJECTIVETo study the effects of carbon disulfide exposure within the national maximum allowable concentration(MAC) on blood pressure and electrocardiogram, and associations with selected factors.
METHODSWorkers in a chemical fiber factory were divided into two groups based on the type of work: a high exposure group (HEG) of 821 individuals and a low exposure group (LEG) of 259. The CS2 concentration at workplace was controlled under the national MAC. A set of 250 randomly selected people taking routine physical check-ups in the same period and hospital constituted the control group. The systolic blood pressure (SBP) and diastolic blood pressure (DBP) were measured on the arm, and the pulse pressure (PP) and mean arterial blood pressure (MABP) were calculated based on SBP and DBP. The blood pressure data, along with the results of the routine 12-lead electrocardiography taken at rest and records on gender, age, years of work, type of work, and concentrations of triglycerol, cholesterol, and glucose in blood, were compiled for analyses. Risk factors upon CS2 exposure for the increase of blood pressure and occurrence of electrocardiogram abnormalities were identified and rationalized.
RESULTSSignificant difference (P < 0.01) in the average values of SBP, DBP, MABP, and the corresponding abnormality incident rates was found between HEG and LEG, and between HEG and the control group. For both HEG and LEG, the incident rate of DBP abnormality (high DBP) is nearly two times as high as that of SBP. Type of work is the largest risk factor in both the high SBP and high DBP subgroups, with odds ratios (OR) of 2.086 and 2.331 respectively, and high CS2 exposure presents more than double the risk than low exposure. On the incident rate of ECG abnormalities, both exposure groups are significantly different (P < 0.01) to the control group. High SBP in LEG and high DBP in HEG were found to be significant risk factors (OR = 3.531 and 1.638 respectively), while blood glucose appears to be a protective factor (OR = 0.747), appealing to further investigation. Meanwhile, factors like years of work and cholesterol were found to be risk factors in the high SBP subgroup with low exposure, and in the high DBP subgroup with high exposure. Within HEG, high DBP is the only blood pressure-related risk factor found for the incident of left ventricular high voltage (OR = 4.140), as is high SBP for LEG (OR = 4.776). High PP is the only risk factor found for repolarization disturbances within LEG (OR = 20.417). While blood sugar is a risk factor for origin disturbances, it is a protection factor for left ventricular high voltage (OR = 0.633).
CONCLUSIONThe damage of CS2 done to the cardiovascular system is a gradual process. Both early and very low level exposures are detrimental to the human circulatory system. Below the National MAC limit, the toxic effect of CS2 to the cardiovascular system increases with time and level of exposure. The effect of CS2 on DBP is more significant than on SBP, which indicates that CS2 may affect peripheral resistant blood vessels more than the artery. The abnormalities of ECG of workers exposed to CS2 are not only the result of high blood pressure on the heart, but also of the direct toxicity of CS2 on heart and blood vessels.
Adult ; Blood Pressure ; drug effects ; Carbon Disulfide ; administration & dosage ; adverse effects ; Electrocardiography ; drug effects ; Female ; Humans ; Male ; Maximum Allowable Concentration ; Middle Aged ; Occupational Exposure ; adverse effects ; Retrospective Studies ; Young Adult
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