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Biomedical subjects

C Winder

Publications and source records attributed to C Winder.

At least 19 recordsLinked to original sources
PubMed2001

The toxicology of chlorine.

Chlorine is a reactive gas used by humanity for over two centuries. Exposure to chlorine has occurred in a number of situations, including as a chemical warfare agent, in industrial and domestic exposures, and as a result of accidents and spills. The toxicology of chlorine is related almost entirely to effects in the respiratory system. A consistent symptomology occurs in both animals and humans. This ranges from sensory irritation, to irritation and bronchospasm, to cellular changes to bronchioles and alveoli, to development of pulmonary disease. While full recovery from such injuries remains the most likely outcome, there is little doubt that permanent loss of function is possible in severe cases. In all industrial applications of chlorine, occupational exposures to chlorine should be controlled to at least the recommended exposure standard. However, a focus of activity on ensuring that excursions (such as leaks or "gassing" incidents) above these values do not occur is likely to be more beneficial. Treatment of chlorine exposure is essentially symptomatic, with the efficacy of some treatments (such as corticosteroid therapy) still not well established.

Animals↗
PubMed2000

Incompatibilities of chemicals.

Chemical incompatibilities are potentially significant problems where hazardous chemicals are found. A number of chemical segregation systems have been developed which provide recommendations for the separation of incompatible chemicals. Three segregation systems were identified in this study: the UN Dangerous Goods system (which uses physical hazard as the main reason for segregation and has 14 categories), the US CHRIS system (which uses chemical reactivity and has 24 categories) and a third system which uses environmental risks (and has 25 categories). These systems were combined. Merging of each system was initially problematic, but became considerably easier once certain characteristics had been defined (such as flammability or water incompatibility). This gave a final merged incompatibility table containing 100 different segregation groups. This research study showed that it was possible to combine different segregation systems based on different criteria and that more comprehensive segregation systems can be developed. These can be of use in the decision-making process about where groups of chemicals may be used, and during the use of chemicals, where chemicals should not be combined. The use of more comprehensive segregation systems will also assist in developing proper measures for their control.

Drug Incompatibility↗
PubMed1999

Assessment of fogging resistance of anti-fog personal eye protection.

The propensity for occupational eye protectors to fog in warm and moist conditions is often offered as a reason by workers not to wear occupational eye protection even where mandatory eye protection areas have been specified. A study of eye protection practices in the New South Wales coal mining industry identified the number one issue in underground coal mine conditions as being fogging of eye safety wear. Conventional anti-fog treatments and cleaners were considered by the miners as completely inadequate in these conditions. At the time of the study claims were being made for a new generation of lens treatments. These merited evaluation. Spectacles and goggles claimed to be fog resistant were obtained from manufacturers and suppliers and subjected to the test set out in BS EN 168 and the compliance criterion of BS EN 166. Some lenses claimed to be fog resistant failed the requirement, some new technology lenses showed arguably superior performance but failed the criterion of the standard. Modifications to the test procedure of BS EN 168 and acceptance criteria of BS EN 166 are proposed.

Coal Mining↗
PubMed1998

Human cell line toxicity of binary and ternary chemical mixtures in comparison to individual toxic effects of their components.

Contaminated site projects involve health risk assessment procedures that must consider potential interactive effects of present contaminants. In order to establish a quick and reliable method that accounts for smaller than additive, additive, or greater than additive toxic effects, this study compared the cytotoxicity of 34 binary and ternary chemical mixtures of four structurally different chemicals to HeLa cells. Further, five blind samples of these mixtures or their components were tested to determine the ability to identify unknown mixtures. The colorimetric MTS in vitro cytotoxicity assay was used to detect cytotoxic effects after the cells were exposed for 1 h to serial dilutions of the mixtures. Experimental cytotoxicity data were compared and set against data predicted by a mathematical algorithm. They mainly showed additive effects of the components in mixture but also identified smaller than additive and greater than additive effects. A subjective classification scheme allowed evaluation of the toxicity of the blind samples in comparison to results from the study on binary and ternary mixtures tested before. This scheme focused on quantitative cytotoxicity data as well as on the slope of the concentration-effect curves and demonstrated the use of the MTS assay for human health risk assessments in the context of contaminated sites.

Cell Survival↗
PubMed1998

Equinins in equine neutrophils: quantification in tracheobronchial secretions as an aid in the diagnosis of chronic pulmonary disease.

Equinins are a closely related group of proteins found in equine neutrophil granules. They demonstrate proteinase inhibiting activity restricted to microbial proteinase K and subtilisin, and they also possess antibacterial and antiviral properties. Antiproteinase K activity was measured in tracheobronchial secretions (TBS) of horses with mild (n = 15), moderate (n = 30) and severe (n = 16) chronic pulmonary disease, to determine its usefulness as an indicator of severity of disease and to measure neutrophil content. Determination of proteinase K inhibiting activity was based on a colorimetric assay measuring the suppression of 4-nitroaniline liberation from the synthetic substrate succinyl-L-alanyl-alanyl-alanin-4-nitroanilid, a process mediated by proteinase K. Proteinase K inhibiting activity proved to be a valid and simple indicator for assessing neutrophil content in TBS and a useful parameter to determine the severity of chronic pulmonary disease in the horse.

Animals↗
PubMed1997

The sensitivity and specificity of the MTS tetrazolium assay for detecting the in vitro cytotoxicity of 20 chemicals using human cell lines.

A number of studies reported that the MTS in vitro cytotoxicity assay is a convenient method for assessing cell viability. The main features found with this assay are its ease of use, accuracy and rapid indication of toxicity. It might well be a useful tool in human health risk assessment if it can be shown that this assay also has an acceptable sensitivity and specificity. This is of interest particularly when exposure to unknown chemical substances requires the rapid detection and evaluation of toxic effects. In this study, the cytotoxicity of 20 chemicals selected from the MEIC priority list was determined with the MTS assay. Since it could be shown that interactions between detection reagents and test chemicals might influence the results of this assay, preliminary experiments were carried out such that artifactual results due to test chemical interference could be excluded from this study. IC50 (50% inhibitory concentration) were established for each test chemical in two human cell lines (F1-73 and HeLa) and later compared with published toxicity data of the same chemicals established with in vitro and in vivo toxicological test systems. Direct comparisons of the data showed a generally lower sensitivity of the MTS assay, which is influenced by biological test organisms, cell type and exposure time. In terms of the specificity of the MTS assay, the results showed a good correlation between data obtained with the MTS assay and published data. The lowest correlation was found when the MTS assay was compared with in vivo studies, however, this finding corresponds well with other published in vitro-in vivo correlations. The highest correlation was found when the MTS assay was compared with test systems using human cell lines or exposure times of 3-24 h. Since the sensitivity of the MTS assay might be increased using different cell types or by extended incubation, this assay is found to provide ideal features of a good measurement system that might also be used for on site toxicological assessments.

Cell Line↗
PubMed1995

Ultrasonographic findings in cows with cholestasis.

Four cows with cholestasis, whose general condition was moderately to severely disturbed, were examined. Two of them had signs of colic, and one had severe pruritus. All of them had jaundice and three had dermatitis solaris. Bilirubinuria occurred in three of the cows and they all had increased concentrations of serum bilirubin and serum bile acids and increased activities of hepatic enzymes. An ultrasonographic examination of the liver and gallbladder revealed that in one cow only the extrahepatic bile ducts were dilated, in another only the intrahepatic bile ducts were dilated and in the other two both the intrahepatic and extrahepatic bile ducts were dilated. In three of the cows the gallbladder was severely dilated and the wall was thickened. Ultrasonographically, the bile appeared either anechoic or echogenic. Surgical or post mortem examinations revealed that the cholestasis in one cow was attributable to obstruction of the common hepatic duct in the area of the hepatic hilus, in two it was caused by obstruction of the common bile duct near the duodenal papilla, and in the fourth cow, the common bile duct was compressed by adhesions, resulting from peritonitis, which involved the liver, gallbladder and abdominal wall.

Animals↗
PubMed1995

Best practice in workplace hazardous substances management.

Chemical-induced injury and disease remains a significant problem in workers in industry. As a result of this problem, a number of national and international initiatives have recommended the development of conventions, regulations, and codes of practice to attempt to deal with the problems of hazardous substances at work. Within Australia, workplace hazardous substances regulations are in development which will impose legal obligations and responsibilities on the suppliers of hazardous substances and on the employers who use them. At the same time, internationally consistent ISO standards are in use, or are being developed, for quality systems, environmental management, and occupational health and safety. These standards outline a model for the management of quality, environment, or safety, and the processes involved are applicable to the management of hazardous substances. This process includes: obtaining commitment from senior management; instituting consultative mechanisms; developing a hazardous substances policy; identifying components of the hazardous substances management program; resourcing, implementing, and reviewing the program; and integrating the program into the organisation's strategic plan. Only by blending in a specific management program for hazardous substances into the overall planning of an organization will they be managed effectively and efficiently.

Accidents, Occupational↗
PubMed1993

A prospective cohort study of the chronic effects of solvent exposure.

The issue of the health effects of long-term exposure to solvents still attracts considerable debate, particularly among regulators and policymakers. This is especially true for studies of neurobehavioral effects. A major reason for this debate is that cross-sectional research designs are almost universally used in this area. Cross-sectional studies suffer from problems of possible confounding by a range of unknown factors and also usually from poor estimates of exposure. This study is an attempt to solve this problem by using an inception cohort design in which the subjects are measured at the beginning of their exposure and then at intervals while their exposure continues. Two hundred first-year apprentice vehicle spray painters were entered into the study within 6 months of beginning their apprenticeship together with a comparison group of 76 first-year apprentice electricians and 49 first-year apprentice metal fabricators. Measures of neurobehavioral function using a test battery based on an information-processing model were made at study entry and will be made annually. In addition apprentice's assessments of their own exposure are being made annually and compared with workplace-exposure assessments. So far measures have been made at the beginning of the second year for the entire cohort and at the beginning of the third year for one-third of the cohort. This paper is a description of the results for this one-third. The results suggest that there were no significant changes in neurobehavioral function in the first 2 years of exposure to solvents. However, the results of workplace monitoring suggest that exposure is considerably below current exposure standards for solvents during this time.

Adolescent↗
PubMed1993

Some toxicological issues in chemical safety and regulation in an Australian context.

This article considers the potential effects on the human body of toxic hazardous substances in general, along with advanced methods of detecting short- and long-term effects of exposure with reference to the results of recent research. In addition to occupational exposure, other contributors to an individual's overall toxic exposure load including environmental and home and lifestyle exposures are also considered in detail. Toxicological information (from diverse sources) and an awareness of the limitations of our present state of knowledge of toxicology are concluded to be important factors in developing chemical safety and regulatory criteria. Although there is some debate concerning the adequacy of the exposure standard-setting process, TWA measures are capable of giving reliable indications of the efficacy of control measures and procedures. Electroencephalogram (EEG) activity reflecting stimulus attention and decision time, electromyography measuring nerve conduction velocities, reaction time, and neuropsychological performance-using batteries of psychometric tests, may all be effective indicators of exposure, interaction with other factors, and long-term effects of exposure.

Australia↗
PubMed1993

The genotoxicity of lead.

Lead has been tested for genotoxic potential in a range of mutagenicity assays. Such studies report varying effects, and the results are equivocal. The reasons for this may be related to problems of the solubility of many lead compounds, their inability to dissolve in biological fluids, chemical interferences resulting in conflicting observations, the nonspecificity of the assays used, the delivery of toxic doses to specific genetic processes or the mediation of genotoxicity through indirect mechanisms. Occupational and environmental exposures to lead have also been associated with increases in chromosomal damage in humans at moderate to high exposures, although this evidence is contradictory. Where positive findings have been reported, many are related to exposure. The possibility that lead is genotoxic is by no means clear, but evidence is still accumulating.

Animals↗
PubMed1993

Workplace toxic incident notification: results of a survey of 16 factory sites in western Sydney.

Workers in the chemical industry are often employed where there is a potential for significant exposure to hazardous materials. Many of these events go unrecorded and are not notified to agencies charged with the responsibility of regulating the workplace. Therefore, a survey was conducted of factories covering a range of activities where poisonous chemicals are in use, aimed at proactively reviewing toxic incident reporting, including (i) underlying principles of notification, (ii) any relevant criteria used in the reporting of incidents, and (ii) compliance with existing legislation. Sixteen factories in the Western Sydney area were inspected by a government safety inspector over a 4-month period. Forty-eight employees were interviewed and data describing 46 exposure events were obtained covering a 12-month period. In all, 10 incidents were identified as significant exposure events, with 5 events (11% of total) at 5 different factories (31% of sites inspected) involving 8 workers (17% of workers interviewed) being definite breaches of statutory accident reporting requirements. The survey revealed a failure by employers to notify significant toxic exposure events due to reluctance or ignorance and or lack of clarity of occupational health and safety regulations. It also revealed that substantial numbers of workers are exposed to incidents involving poisonous materials, and that with this nonnotification, regulatory agencies are largely unaware of their magnitude.

Australia↗
PubMed1993

Classification of hazardous materials by oral, dermal, and inhalational toxicities.

Currently, no toxicity classification system exists in any formal sense for dermal and inhalational toxicities (the main routes of exposure in occupational environments), and, different criteria are used by regulatory agencies in the classification of toxicity by these routes. Therefore, a comparison of the acute toxicity information available for 582 chemicals with exposure standards was made with a view to establishing such a toxicity classification system. By sorting data on the basis of oral toxicity values, and dividing these values into toxicity classes (such as slightly toxic, very toxic, supertoxic), a strong correlation was found to exist between oral and dermal toxicity values, and oral and inhalational toxicity values. Indeed, overlap across toxicity classes was very small, and in most cases, clear demarcations existed. A toxicity classification system is proposed from these data. This classification system is based on a comparison of actual toxicity data, and is a true reflection of the interrelationships between oral, dermal, and inhalational toxicities.

Administration, Inhalation↗
PubMed1992

Solvent exposure and related work practices amongst apprentice spray painters in automotive body repair workshops.

As part of a multidisciplinary study into the health effects of solvents, workplace assessments and airborne solvent vapour monitoring was conducted in 46 spray painting workshops in the Sydney metropolitan area. Breathing-zone samples were taken from 50 apprentices and 14 experienced spray painters. An interview schedule was developed to obtain information about the use of acrylic or two-pack paint systems, the use of engineering controls, the use of personal protective equipment and the availability of material safety data sheets. Contaminants typical of the chemical products used in this industry were encountered (aromatic hydrocarbons, C5-C7 aliphatic hydrocarbons, ketones, esters). The results of airborne solvent monitoring indicate a total solvent exposure in the range 1-99% of a combined Worksafe Australia exposure standard, with a mean of 19%. Solvent exposure was highest when spraying acrylic paint in the open workshop and lowest when spraying two pack paint in a spray booth. Much the same personal protective equipment was available in all workshops, but wide variation in its use was observed. Material safety data sheets were not observed in any of the workshops.

Automobiles↗