Silicosis, asbestosis, and pulmonary fibrosis in Ontario, Canada from 1996 to 2019.

BACKGROUND: Silicosis is a fibrotic lung disease caused by exposure to respirable crystalline silica. Historically, silicosis was common among miners and other professions in the 20th century, and in recent decades has re-emerged in coal mining and appeared in new workplaces, including the manufacture of distressed jeans and artificial stone countertops. METHODS: Physician billing data for the province of Ontario between 1992 and 2019 were analyzed across six time-periods (1993-1995, 1996-2000, 2001-2005, 2006-2010, 2011-2015, and 2016-2019). The case definition was two or more billing records within 24 months with a silicosis diagnosis code (ICD-9 502, ICD-10 J62). Cases from 1993 to 1995 were excluded as prevalent cases. Crude incidence rates per 100,000 persons were calculated by time-period, age, sex, and region. Analyses were repeated in parallel for pulmonary fibrosis (PF) (ICD-9 515, ICD-10 J84) and asbestosis (ICD-9 501; ICD-10 J61). RESULTS: From 1996 to 2019, 444 cases of silicosis, 2719 cases of asbestosis and 59,228 cases of PF were identified. Silicosis rates decreased from 0.42 cases per 100,000 in 1996-2000 to 0.06 per 100,000 people in 2016-2019. A similar trend was observed for asbestosis (1.66 to 0.51 per 100,000 persons) but the incidence rate of PF increased from 11.6 to 33.9 per 100,000 persons. Incidence rates for all outcomes were higher among men and older adults. CONCLUSIONS: A decreasing incidence of silicosis was observed in this analysis. However, the incidence of PF increased, consistent with findings from other jurisdictions. While cases of silicosis have been recorded among artificial stone workers in Ontario these cases do not seem to have impacted the population rates thus far. Ongoing, periodic surveillance of occupational diseases is helpful for tracking population-level trends over time.

Emissions and health risks from the use of 3D printers in an occupational setting.

The aim of this study was to determine concentrations of particulates and volatile organic compounds (VOCs) emitted from 3D printers using polylactic acid (PLA) filaments at a university workroom to assess exposure and health risks in an occupational setting. Under typical-case (one printer) and worst-case (three printers operating simultaneously) scenarios, particulate concentration (total and respirable), VOCs and formaldehyde were measured. Air samples were collected in the printing room and adjacent hallway. Size-resolved levels of nano-diameter particles were also collected in the printing room. Total particulate levels were higher in the worst-case scenario (0.7 mg/m3) vs. typical-case scenario (0.3 mg/m3). Respirable particulate and formaldehyde concentrations were similar between the two scenarios. Size-resolved measurements showed that most particles ranged from approximately 27 to 116 nm. Total VOC levels were approximately 6-fold higher during the worst-case scenario vs. typical situation with isopropyl alcohol being the predominant VOC. Airborne concentrations in the hallway were generally lower than inside the printing room. All measurements were below their respective occupational exposure limits. In summary, emissions of particulates and VOCs increased when multiple 3D printers were operating simultaneously. Airborne levels in the adjacent hallway were similar between the two scenarios. Overall, data suggest a low risk of significant and persistent adverse health effects. Nevertheless, the health effects attributed to 3D printing are not fully known and adherence to good hygiene principles is recommended during use of this technology.

Assessing health impacts of the December 2013 Ice storm in Ontario, Canada.

BACKGROUND: Ice, or freezing rain storms have the potential to affect human health and disrupt normal functioning of a community. The purpose of this study was to assess acute health impacts of an ice storm that occurred in December 2013 in Toronto, Ontario, Canada. METHODS: Data on emergency department visits were obtained from the National Ambulatory Care Reporting System. Rates of visits in Toronto during the storm period (December 21, 2013 - January 1, 2014) were compared to rates occurring on the same dates in the previous five years (historical comparison) and compared to those in a major unaffected city, Ottawa, Ontario (geographic comparison). Overall visits and rates for three categories of interest (cardiac conditions, environmental causes and injuries) were assessed. Rate ratios were calculated using Poisson regression with population counts as an offset. Absolute counts of carbon monoxide poisoning were compared descriptively in a sub-analysis. RESULTS: During the 2013 storm period, there were 34 549 visits to EDs in Toronto (12.46 per 1000 population) compared with 10 794 visits in Ottawa (11.55 per 1000 population). When considering year and geography separately, rates of several types of ED visits were higher in the storm year than in previous years in both Toronto and Ottawa. Considering year and geography together, rates in the storm year were higher for overall ED visits (RR: 1.10, 95 % CI: 1.09-1.11) and for visits due to environmental causes (RR: 2.52, 95 % CI: 2.21-2.87) compared to previous years regardless of city. For injuries, visit rates were higher in the storm year in both Toronto and Ottawa, but the increase in Toronto was significantly greater than the increase in Ottawa, indicating a significant interaction between geography and year (RR: 1.23, 95 % CI: 1.16-1.30). CONCLUSIONS: This suggests that the main health impact of the 2013 Ice Storm was an increase in ED visits for injuries, while other increases could have been due to severe weather across Ontario at that time. This study is one of the first to use a population-level database and regression modeling of emergency visit codes to identify acute impacts resulting from ice storms.

Acute and chronic respiratory symptoms among primary care patients who smoke crack cocaine.

Among inner-city populations in Canada, the use of crack cocaine by inhalation is prevalent. Crack smoking is associated with acute respiratory symptoms and complications, but less is known about chronic respiratory problems related to crack smoking. There is also a gap in the literature addressing the management of respiratory disease in primary health care among people who smoke crack. The purpose of our study was to assess the prevalence of acute and chronic respiratory symptoms among patients who smoke crack and access primary care. We conducted a pilot study among 20 patients who currently smoke crack (used within the past 30 days) and who access the "drop-in clinic" at an inner-city primary health care center. Participants completed a 20- to 30-min interviewer-administered survey and provided consent for a chart review. We collected information on respiratory-related symptoms, diagnoses, tests, medications, and specialist visits. Data were analyzed using frequency tabulations in SPSS (version 19.0). In the survey, 95 % (19/20) of the participants reported having at least one respiratory symptom in the past week. Thirteen (13/19, 68.4 %) reported these symptoms as bothersome. Chart review indicated that 12/20 (60 %) had a diagnosis of either asthma or chronic obstructive pulmonary disease (COPD), and four participants (4/20, 20 %) had a diagnosis of both asthma and COPD. Majority of the participants had been prescribed an inhaled medication (survey 16/20, 80 %; chart 12/20, 60 %). We found that 100 % (20/20) of the participants currently smoked tobacco, and 16/20 (80 %) had smoked both tobacco and marijuana prior to smoking crack. Our study suggests that respiratory symptoms and diagnoses of asthma and COPD are prevalent among a group of patients attending an inner-city clinic in Toronto and who also smoke crack. The high prevalence of smoking tobacco and marijuana among our participants is a major confounder for attributing respiratory symptoms to crack smoking alone. This novel pilot study can inform future research evaluating the primary health care management of respiratory disease among crack smokers, with the aim of improving health and health care delivery.