Relationships between inhalable and total hexavalent chromium exposures in steel passivation, welding and electroplating operations of Ontario.

The main aim of the study was to assess the relationship between inhalable hexavalent chromium and "total" hexavalent chromium. Air sampling was conducted at steel passivation operation of a steel manufacturer at a stainless steel welding operation and at two hard chrome electroplaters. Air samples were taken side-by-side for "total" dust using closed-face 37-mm diameter cassette samplers and for inhalable dust using Institute of Occupational Medicine inhalable samplers.

Aluminum in the lungs of Ontario hardrock miners.

The objective of this study was to determine the concentration of aluminum in the autopsied lungs of eight hardrock miners. These miners had inhaled McIntyre Powder (a mixture of aluminum and aluminum oxide) as a prophylaxis against silicosis. The study involved chemical analysis of lungs, where each whole lung was divided horizontally into three sections and analyzed by atomic absorption spectrophotometer equipped with a graphite furnace.

Evaluation of Firefighter Exposure to Wood Smoke during Training Exercises at Burn Houses.

Smoke from wood-fueled fires is one of the most common hazards encountered by firefighters worldwide. Wood smoke is complex in nature and contains numerous compounds, including methoxyphenols (MPs) and polycyclic aromatic hydrocarbons (PAHs), some of which are carcinogenic. Chronic exposure to wood smoke can lead to adverse health outcomes, including respiratory infections, impaired lung function, cardiac infarctions, and cancers.

Retrospective Exposure Assessment for Occupational Disease of an Individual Worker Using an Exposure Database and Trend Analysis.

This article outlines a hierarchy of data required for retrospective exposure assessment for occupational disease of an individual worker. It then outlines in a step-wise manner how trend analysis using a relatively large exposure database can be used to estimate such exposure. The process of how a large database containing exposure measurements can be prepared for estimating historic occupational exposures of individual workers in relation to their illnesses is described.

Respirable dust and respirable silica exposure in Ontario gold mines.

A comprehensive survey of respirable dust and respirable silica in Ontario gold mines was conducted by the Ontario Ministry of Labor during 1978-1979. The aim was to assess the feasibility of introducing gravimetric sampling to replace the assessment method which used konimeters, a device which gave results in terms of number of particles per cubic centimeter (ppcc) of air. The study involved both laboratory and field assessments.

Metals in the lungs of Ontario hardrock miners.

The objective of this study was to determine the concentration of nickel, cadmium, and lead in the autopsied lungs of 29 hardrock miners. It involved chemical analysis of the lungs, where each lung was divided horizontally into 3 sections and analyzed by an atomic absorption spectrophotometer equipped with a graphite furnace. The grand mean levels of nickel, cadmium, and lead were found to be 1.

Occupational health and safety issues in Ontario sawmills and veneer/plywood plants: a pilot study.

A pilot study was conducted within the Ontario sawmill and veneer/plywood manufacturing industry. Information was collected by postal questionnaire and observational walk-through surveys. Industrial hygiene walk-through surveys were conducted at 22 work sites, and measurements for wood dust, noise, and bioaerosol were taken.

Silica exposure assessment in a mortality study of Vermont granite workers.

A study of past silica and respirable dust exposures in the Vermont granite industry was conducted to develop a job exposure matrix (JEM) that used 5204 industrial hygiene measurements made from 1924-2004. The construction of the JEM involved data entry from several original sources into an Excel database that was reviewed later to ensure accuracy. Exposure measurements by job or location were grouped in two broad categories of quarry or shed and then into 22 job classes.

Mortality in Vermont granite workers and its association with silica exposure.

To assess mortality in Vermont granite workers and examine relationships between silica exposure and mortality from lung cancer, kidney cancer, non-malignant kidney disease, silicosis and other non-malignant respiratory disease. Methods Workers employed between 1947 and 1998 were identified. Exposures were estimated using a job-exposure matrix.

A cohort study of traffic-related air pollution and mortality in Toronto, Ontario, Canada.

Background: Chronic exposure to traffic-related air pollution (TRAP) may contribute to premature mortality, but few studies to date have addressed this topic.

Objectives: In this study we assessed the association between TRAP and mortality in Toronto, Ontario, Canada.

Methods: We collected nitrogen dioxide samples over two seasons using duplicate two-sided Ogawa passive diffusion samplers at 143 locations across Toronto.

Computed tomographic enterography and enteroclysis: pearls and pitfalls.

Computed tomographic (CT) enterography and enteroclysis improve visualization of the small bowel mucosa and wall in comparison with traditional CT and fluoroscopic studies by distending the small bowel through enteric hyperhydration with a negative contrast agent. Although CT enterography is performed with oral hyperhydration, CT enteroclysis requires the placement of an enteroclysis tube, often in patients who are unable to orally consume the amount of liquid. When tolerated, CT enterography is often preferred due to its lack of invasiveness.

Dust content of lungs and its relationships to pathology, radiology and occupational exposure in Ontario hardrock miners.

Background: Autopsied lungs from 29 hard rock miners were investigated to determine the relationship of the dust content to pathology, radiology, and occupational exposure.

Methods: Each lung was divided horizontally into three sections. Pathological and radiological studies and chemical analyses were carried out on samples from each section.

Relationships between inhalable, thoracic, and respirable aerosols of metalworking fluids.

The aim of the study described in this companion paper was to assesses relationships among inhalable, thoracic, and respirable aerosol fractions of metalworking fluids. A RespiCon sampler, which simultaneously collects all three fractions, was used at four Ontario plants to collect 37 samples of 120 to 400 min duration. The ratios of the slopes of the lines of a regression model forced through the origin between inhalable and thoracic, inhalable and respirable, and thoracic and respirable were 1.

An evaluation of analytical methods, air sampling techniques, and airborne occupational exposure of metalworking fluids.

This article summarizes an assessment of air sampling and analytical methods for both oil and water-based metalworking fluids (MWFs). Three hundred and seventy-four long-term area and personal airborne samples were collected at four plants using total (closed-face) aerosol samplers and thoracic samplers. A direct-reading device (DustTrak) was also used.

Mortality and cancer incidence in Ontario glass fiber workers.

Background: In a previous cohort study of glass fiber manufacturing, we found a significant increase in lung cancer. This study extends the follow-up period.

Methods: We conducted a historical prospective study of 2557 men employed in producing glass wool.

Occupational exposure limits: an approach and calculation aid for extended work schedule adjustments.

Past reviews of occupational exposure limit (OEL) adjustments have covered both decision logic and calculation methods to derive factors to assure protection of workers on extended (also known as unusual) work shifts. The approaches reviewed included several Haber's rule based methods, several variants of single compartment toxicokinetic (TK) models, and physiologically based pharmacokinetic modeling. These models calculate OEL adjustment factors based on the work shift and the uptake and elimination of the toxicant.

A simultaneous job- and task-based exposure evaluation of petroleum tanker drivers to benzene and total hydrocarbons.

A simultaneous job- and task-based exposure study was conducted for tanker drivers delivering petroleum products from several bulk terminals and an agency to retail outlets. Full-shift (job-based) samples and job component tasks samples were collected simultaneously. The tasks sampled included loading, unloading, and travel.

Mortality among Ontario members of the International Union of Bricklayers and Allied Craftworkers.

Background: Dust exposed workers may be at increased risk of pneumoconiosis, stomach cancer, lung cancer, and obstructive lung disease. Bricklayers may experience high exposures to silica and inorganic dusts. The aim of this study was to examine the mortality pattern of bricklayers to identify occupational associations with mortality.

Current man-made mineral fibers (MMMF) exposures among ontario construction workers.

Current occupational exposures to man-made mineral fibers (MMMF), including refractory ceramic fibers (RCF), were measured as part of an exposure assessment program for an epidemiological study pertaining to cancer and mortality patterns of Ontario construction workers. The assessments were carried out at commercial and residential sites. A total of 130 MMMF samples (104 personal and 26 area) was collected and included 21 RCF (16 personal and 5 area).

Ischemic heart disease mortality among heavy equipment operators.

Background: Inhalation of fine particulate is hypothesized to increase risk of heart disease events.

Methods: Seven Ontario construction unions participated in a retrospective cohort mortality study. Proportional mortality ratios (PMRs) were computed and a mortality odds ratio (MOR) analysis was performed to compare the risk of ischemic heart disease (IHD) mortality among heavy equipment operators (HEO) to that of members of other unions.