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Biomedical subjects

K Teschke

Publications and source records attributed to K Teschke.

At least 73 records · Page 4Linked to original sources
PubMed1992

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.

Acute Disease↗
PubMed1991

Paternal occupation and congenital anomalies in offspring.

This paper presents the results of an exploratory case-control study of paternal occupation as a risk factor for birth defects in offspring. With the use of a population-based registry in British Columbia, 14,415 liveborn children with birth defects were identified for the period, 1952-1973. Two controls were matched to each case by using the birth files of British Columbia. Paternal occupation was obtained from the birth certificate. The analysis included 20 birth defect categories. Paternal occupations found to be associated with an increased odds ratio (OR) of birth defects include janitors [hydrocephalus (OR = 5.04), ventricular septal defects (OR = 2.45), other heart defects (OR = 2.35)], forestry and logging workers [congenital cataract (OR = 2.28), atrial septal defects (OR = 2.03), syndactyly (OR = 2.03)], painters [spina bifida (OR = 3.21), patent ductus arteriosus (OR = 2.34), cleft palate (OR = 3.36)], printers [atresia of the urethra (OR = 4.50), clubfoot (OR = 2.18)], and plywood mill workers [patent ductus arteriosus (OR = 2.52), pyloric stenosis (OR = 4.12), dislocated hip (OR = 2.71)]. This study has several limitations and the results must be viewed with caution. Nonetheless, the study provides new leads for further evaluation of the role of father's occupation in the etiology of birth defects.

British Columbia↗
PubMed1991

A hierarchical coding system for occupational exposure.

A 10-digit hierarchical method for coding occupationally encountered chemicals offering significant advantages over existing chemical coding systems has been developed and tested. With this unique system, substances are categorized and coded according to their composition and physical natures. Consequently, compounds of similar structure may be distinguished, and classes of similar compounds (for example, all halogenated organic compounds, all inorganic sulfates) can be readily retrieved. This novel coding system was developed to assist primarily in the identification of potential carcinogens in occupational studies using job exposure matrices. However, the system has wider applications as it can be employed by industry to facilitate data management and monitoring programs in the workplace.

Carcinogens↗
PubMed1990

Using noise exposure histories to quantify duration of vibration exposure in tree fallers.

A study of tree fallers in the British Columbia forest industry was done to determine if noise histories could be used to monitor the daily duration of exposure to hand-arm vibration from chain saws. Field observations and noise dosimetry showed that chain saw noise was distinguishable from other sound sources in fallers' work environments. Using data from noise dosimetry synchronized with observations of fallers' chain saw use, a model of sound pressure levels predictive of chain saw operating mode was developed. Subsequent workday noise histories of 13 fallers showed that the chain saw was off for an average of 331 +/- 27 min, idling for 91 +/- 11 min, and cutting wood for 96 +/- 7 min. This method could be used to collect data to refine dose-response estimates for vibration syndrome or to monitor administrative controls of vibration exposure time.

British Columbia↗
PubMed1990

Birth defects among offspring of firemen.

The authors conducted an exploratory case-control study of paternal employment as a fire fighter and the risk of birth defects among offspring. By means of a population-based registry in British Columbia, 22,192 liveborn children with birth defects were identified for the period, 1952-1973. Two comparisons were made to evaluate the risk among offspring of firemen: 1) comparison with the risk among offspring of fathers employed in other occupations using a matched (two per case) control group, and 2) comparison with the risk among offspring of policemen. Among the 20 birth defect groups studied, an association was found for paternal employment as a fire fighter (relative to all other occupations) and increased risks were observed for ventricular septal defects (odds ratio (OR) = 2.70, 95% confidence interval (Cl) 1.02-7.18) and atrial septal defects (OR = 5.91, 95% Cl 1.60-21.83) among offspring. When compared with policemen, firemen had increased risks of having a child with a ventricular septal defect (OR = 4.68, 95% Cl 1.66-13.17) and atrial septal defect (OR = 3.76, 95% Cl 1.40-10.07). Analyses using a pathogenetic classification for these heart defects yielded similar increased odds ratios for firemen.

Case-Control Studies↗
PubMed1989

Potential exposure of cooks to airborne mutagens and carcinogens.

Recent case-control and proportionate mortality studies in Canada, the United States, Britain, and Denmark have shown that cooks and other food-service workers may have elevated risks of cancers of the nasopharynx, buccal cavity, esophagus, lung, and bladder. The purpose of this pilot study was to determine if there might be airborne products of cooking which may be risk factors for these cancers in cooks. Eight air samples were taken in four restaurants and subsequently analyzed for mutagenicity using the Ames assay, and for carcinogens using gas chromatography/mass spectrometry. All four samples taken in the restaurant cooking areas were mutagenic to TA98 without metabolic activation, and two were mutagenic to TA100 also without metabolic activation. Of the four dining area samples, one was mutagenic to TA100 and one to TA98, both without metabolic activation. Compounds tentatively identified by mass spectrometry did not include known carcinogens. The ventilation systems in all four restaurants allow the exposure of cooks to both the air from dining room smoking areas and the volatile products of cooking.

Air Pollutants, Occupational↗
PubMed1989

A comparison of exposure estimates by worker raters and industrial hygienists.

The validity and reliability of nine senior sawmill workers' estimates of frequency, duration, and routes of exposure were compared with individual workers' ratings of their own job titles and industrial hygienists' ratings of all job titles in the plant. The reliability of the senior workers' mean exposure estimates [group intraclass correlation coefficient (ICC) = 0.71] compared favorably with those of three pairs of hygienists (group ICC = 0.57, 0.67, and 0.81). The validity of their ratings was assessed in a comparison with urinary chlorophenate measurements representing 92% of the job titles in the sawmill. The senior workers' ratings [coefficient of determination (R2) = 0.22] resembled those of two pairs of industrial hygienists (R2 = 0.24, 0.22) and was significantly greater than that of the third pair (R2 = 0.08). The validity of the self-reports was also low (R2 = 0.15), but the difference was not statistically significant. Senior workers' exposure ratings appear to be as effective as the other methods tested.

Air Pollutants, Occupational↗
PubMed1989

Paternal occupational exposures and the risk of Down syndrome.

An exploratory case-control study of paternal occupation as a risk factor for Down syndrome was conducted. With the use of the British Columbia Health Surveillance Registry, 1,008 cases of live-born Down syndrome were identified for the period 1952-73. Two controls were matched to each case by using the birth files of British Columbia. Paternal occupation was obtained from the birth notice. Elevated maternal age-adjusted relative risks of Down syndrome were found for fathers employed as janitors (odds ratio [OR] = 3.26; 95% confidence interval [C.I.] = 1.02-10.44); mechanics (OR = 3.27; C.I. = 1.57-6.80); farm managers/workers (OR = 2.03; C.I. = 1.25-3.03); material-moving equipment operators (OR = 1.88; C.I. = 0.93-3.82); food processors (OR = 1.79; C.I. = 0.96-3.31); sheet-metal workers, iron workers, and other metalworkers (OR = 1.57; C.I. = 0.92-2.69); and sawmill workers (OR = 1.43; C.I. = 0.90-2.66). This large study provides new leads for further evaluation of the role of paternal exposures in the etiology of Down syndrome.

British Columbia↗
PubMed1988

Validity and reliability of a method for retrospective evaluation of chlorophenate exposure in the lumber industry.

This paper describes the validity and reliability of a method to retrospectively assess exposure to antisapstain agents used in sawmills (chlorophenates). The method is based on experienced workers' estimates of exposure for each job title at the sawmill where they work. At a pilot mill, 10 randomly selected workers estimated the frequency and duration of exposures to chlorophenates for all 59 job titles. The reliability of their mean exposure estimates was very high, with an intraclass correlation coefficient for all raters of 0.91 (based on a calculated index of exposure). To assess validity, urinary chlorophenate levels were measured for 86% of the workers at the mill during the summer and/or fall, and compared to experienced workers' estimates of exposure. The correlation between workers' exposure estimates and the urinary chlorophenate levels for each job title were consistently above 0.65 for all analyses and greater than 0.72 when summer and fall urine sample results were averaged. The evidence indicates that the validity and reliability of worker exposure estimates are high enough to justify investigation of the method's generalizability to other sawmills.

Chlorophenols↗
PubMedDate not supplied

Studying the determinants of exposure: a review of methods.

To better understand where, when, and how to control occupational exposures, it is vital that hygienists understand the factors that contribute to elevated or reduced exposure levels. Over the last two decades a burgeoning literature examining the determinants of exposure has developed, yet to date the methods used in this regard have rarely been summarized in texts or elsewhere. The purpose of this article is to provide an overview of the techniques used to study the predictors of workplace exposures. Both experimental and observational studies are examined, and the advantages and limitations of each are discussed. Fundamental study design features are reviewed. These include the selection and measurement of factors potentially related to exposure, as well as the measurement of exposure itself. Decisions reached by investigators in selecting the number of sites and workers, the number of repeated observations per worker, and the duration of sampling are discussed. Also examined are issues that commonly arise in the course of data analysis of exposure determinants. These include transformation of exposure variables, correlation of predictor variables, empirical model building, and interpretation of results. Finally, methods employed to evaluate the validity of findings are summarized.

Environmental Monitoring↗
PubMedDate not supplied

Occupational exposure to chemical and biological agents in the nonproduction departments of pulp, paper, and paper product mills: an international study.

As part of an international epidemiological study of workers in the pulp and paper industry, previously unpublished exposure measurements were assembled in a database. This article describes 7293 measurements in nonproduction departments from 147 mills in 11 countries. The greatest variety of agents was measured in the maintenance, construction, and cleaning department, where high exposures to asbestos, chromium [VI] compounds, copper, mercury in urine, nitrogen dioxide, ozone, styrene, sulfur dioxide, trichloroethylene, and welding fumes were observed. Measurements in the storage, yard, loading, and shipping department indicated high exposures to asbestos, carbon monoxide, fungal spores, nitrogen oxides, sulfur dioxide, and total dust. The steam and power generation department had high exposures to methyl mercaptan, silica, and total dust. Measurements in process and effluent water treatment, laboratory and research, engineering, and office, administration, and cafeteria areas had few elevated exposures. Throughout the nonproduction departments, measurements of pulp-production chemicals such as chlorine and sulfur compounds tended to be low, with many below detection limits. There were some problems with the available data; in particular, detection limits were often not specified, and the data tended to be clustered in such a way that sources of exposure variability could not be distinguished. Despite these problems, the data provide new insight into the exposures of nonproduction pulp and paper industry personnel.

Databases, Factual↗
PubMedDate not supplied

Community risk perception and waste management: a comparison of three communities.

Three cross-sectional surveys were conducted in different regions of British Columbia, using a model of risk perception that divides the community into attitudinal and behavioral subgroups based on awareness and concern about waste management facilities. The three communities differed with respect to their levels of both awareness and concern about facilities, either planned for or situated in their region. Surprisingly, the most polarized community, which had nevertheless accepted a facility, rated this facility as more desirable than the other two communities. The unconcerned group in this community felt well informed, was more trusting of siting and operating agencies, and believed that the facility would generate benefits. The concerned group in this community also felt better informed, was more trusting of siting and operating agencies, and believed that its facility would generate benefits, compared with concerned groups in the other two communities. Longitudinal studies of the attitudes driving the siting process are needed to understand how these relationships evolve over time.

Adult↗
PubMedDate not supplied

Exposure to dust, resin acids, and monoterpenes in softwood lumber mills.

A study to assess exposure to potential respiratory hazards in a large lumber mill processing spruce (Picea engelmannii and glauca), pine (Pinus contorta), and fir (Abies lasiocarpa) used a random sampling strategy to assess exposures for all jobs in the sawmill, planer mills, and yard. Personal samples for inhalable particulate were collected to measure exposure to dust and resin acids (abietic acid and pimaric acid). To estimate wood dust exposure, rather than overall dust, the resin acid content within dust was used in combination with observations of job tasks and proximity to dust sources. Passive dosimeters were used to measure exposure to alpha-pinene, beta-pinene, delta3-carene, and other unidentified wood volatiles suspected to be monoterpenes. The GM of the 220 inhalable particulate samples was 1.0 mg/m3 whereas the mean abietic acid, pimaric acid, and estimated wood dust levels were 7.2 microg/m3, 0.6 microg/m3, and 0.5 mg/m3, respectively. The GMs of the 222 monoterpene samples were 0.1 mg/m3 for alpha-pinene, 0.3 mg/m3 for beta-pinene, 0.1 mg/m3 for delta3-carene, and 0.5 mg/m3 for the unidentified wood volatiles. Monoterpene exposures were much lower than those observed in other studies conducted in Sweden and Finland. The results of this exposure assessment highlight the importance of considering the content of airborne particulates in lumber mills as well as potential exposure to wood chemicals.

Abietanes↗
PubMedDate not supplied

Sources of dioxins and furans in British Columbia.

A recent Canadian study of the levels of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) in adipose tissue suggested higher levels in British Columbians than in other Canadians. This led to concerns about the sources of these compounds in B.C. In this paper, we review scientific publications to generate a list of possible sources of PCDDs and PCDFs. We outline which of these are likely to be found in British Columbia, and develop hypotheses concerning their potential contribution to an individual's "PCDD/PCDF load". Further sampling and analysis of British Columbians' adipose tissue could test hypotheses about occupational and environmental exposures to dioxins and furans.

British Columbia↗
PubMedDate not supplied

Environmental risk analysis: a case study.

Traditional risk analysis which has evolved to fit the requirements of regulatory agencies, is often too time-consuming and cumbersome for specific environmental decision making activities in public health. For instance, the discovery of an old chemical landfill operation may require highly focussed risk information to help make a decision to abandon, decontaminate, or develop the site. This paper presents an alternate approach to risk analysis which is more efficient than traditional methods in assessing the human health risks associated with specific development plans. The method is illustrated with an example of a building site in British Columbia.

Child↗
PubMedDate not supplied

Community risk perception: a case study in a rural community hosting a waste site used by a large municipality.

Using a model of risk perception which divides the community into attitudinal and behavioural subgroups based on awareness, concern and action in relation to a waste management facility, we conducted a survey in a community with an operating landfill and a ten-year history of controversy over the unsuccessful siting of a hazardous waste facility (HWF). The purpose of the survey was to study community attitudes to waste management in general, attitudes specific to landfills and HWFs, and to identify factors which shape community attitudes in both cases. Levels of concern and activism were lower for the landfill; activism and concern were more likely among younger subjects and those with children. In the case of the HWF, greater concern and activism were more likely among married people and those without a university education. Gender differences in relation to environmental "concern" were not found for either the landfill or the HWF siting attempts.

Adult↗
PubMedDate not supplied

Risk perception differences in a community with a municipal solid waste incinerator.

Using a community model of risk perception, we conducted an environmental risk perception survey in a community with an operating municipal solid waste incinerator to further understanding of community responses to technology perceived as "hazardous". The specific aims of the survey were to study attitudes to waste management (incineration in particular) and to identify sociological attributes which help shape community attitudes to the facility. Approximately one third of the community were unaware of the incinerator. Those unaware gave lower desirability ratings to incinerator technology than the aware group. About half of the aware group were concerned about the facility and rated the incinerator in the same way as those who were unaware; however, the remainder (the unconcerned) appear to have accepted the incinerator. The results of this cross-sectional study suggest that informing the public about technology perceived as hazardous may not lead to alarm, but may in fact increase acceptance.

Attitude to Health↗