Occupational, Environmental, and Climate Medicine Program

Cycle Threshold to Test Positivity in COVID-19 for Return to Work Clearance in Health Care Workers

Sandra Domeracki, RN, MSN, FNP-BC, COHN-S, FAAOHN
Robert N Clapp
Kristopher Taylor
Chuanyi M Lu
Harry Lampiris
Paul D Blanc
2020

Objective: To ascertain whether reverse transcriptase polymerase chain reaction (RT-PCR) cycle amplifications until detection, the cycle threshold (Ct), could help inform return to work (RTW) strategies for health care workers (HCWs) recovering from COVID-19 infection.

Methods: Sequential Ct data from COVID-19 nasal pharyngeal (NP) RT-PCR testing in all COVID-19 positive HCWs at a single institution. Analysis of Ct in relation to time until negative testing for RTW clearance.

Results: Data for 12 employees showed that time...

Excess mortality associated with the COVID-19 pandemic among Californians 18–65 years of age, by occupational sector and occupation: March through November 2020

Yea-Hung Chen
Maria Glymour
Alicia Riley
John Balmes, MD
Kate Duchowny
Robert Harrison
Ellicott Matthay
Kirsten Bibbins-Domingo
2021

Background
Though SARS-CoV-2 outbreaks have been documented in occupational settings and in-person essential work has been suspected as a risk factor for COVID-19, occupational differences in excess mortality have, to date, not been examined. Such information could point to opportunities for intervention, such as vaccine prioritization or regulations to enforce safer work environments.

Methods and findings
Using autoregressive integrated moving average models and California Department of Public Health data representing 356,188 decedents 18–65 years of age who died between...

Modulation of the Microbiome in Parkinson's Disease: Diet, Drug, Stool Transplant, and Beyond

Ethan G Brown
Samuel M Goldman
2020

The gastrointestinal microbiome is altered in Parkinson's disease and likely plays a key role in its pathophysiology, affecting symptoms and response to therapy and perhaps modifying progression or even disease initiation. Gut dysbiosis therefore has a significant potential as a therapeutic target in Parkinson's disease, a condition elusive to disease-modifying therapy thus far. The gastrointestinal environment hosts a complex ecology, and efforts to modulate the relative abundance or function of established microorganisms are still in their infancy. Still, these techniques are being...

Traumatic brain injury and α-synuclein: Proceed with caution

Ethan G Brown
Samuel M Goldman
2020

No abstract available

The Effect of the COVID-19 Pandemic on People with Parkinson's Disease

Ethan G Brown
Lana M Chahine
Samuel M Goldman
Monica Korell
Emerald Mann
Daniel R Kinel
Vanessa Arnedo
Kenneth L Marek
Caroline M Tanner
2020

Background: The effect of the COVID-19 pandemic on people with Parkinson's disease (PD) is poorly understood.

Objective: To rapidly identify areas of need and improve care in people with PD during the COVID-19 pandemic, we deployed a survey to assess COVID-19 symptoms and the pandemic's effect among those with and without COVID-19.

Methods: People with and without PD participating in the online study Fox Insight (FI) were invited to complete a survey between April 23 and May 23, 2020. Among people reporting COVID-19 diagnoses...

The joint effect of ambient air pollution and agricultural pesticide exposures on lung function among children with asthma

Wande Benka-Coker
Lauren Hoskovec
Rachel Severson
John Balmes, MD
Ander Wilson
Sheryl Magzamen
2020

Background: Ambient environmental pollutants have been shown to adversely affect respiratory health in susceptible populations. However, the role of simultaneous exposure to multiple diverse environmental pollutants is poorly understood.

Objective: We applied a multidomain, multipollutant approach to assess the association between pediatric lung function measures and selected ambient air pollutants and pesticides.

Methods: Using data from the US EPA and California Pesticide Use Registry, we reconstructed three months prior...

Place Matters: Residential Racial Segregation and Chronic Obstructive Pulmonary Disease

John R Balmes
2021

No abstract available

The Changing Nature of Wildfires: Impacts on the Health of the Public

John R Balmes
2020

Catastrophic wildfires are increasing around the globe as climate change continues to progress. Another risk factor for large wildfires in the western United States is a legacy of fire suppression that has allowed overgrowth of underbrush and small trees in forests where periodic lightning-sparked wildfires are part of the natural ecosystem. Wildfire smoke contains CO2, CO, NOx, particulate matter, complex hydrocarbons (including polycyclic aromatic hydrocarbons), and irritant gases, including many of the same toxic and carcinogenic substances as cigarette smoke. The public...

Occupation versus environmental factors in hypersensitivity pneumonitis: population attributable fraction

Hayley Barnes
Anna-Carin Olin
Kjell Torén
Charles McSharry
Iona Donnelly
Mona Lärstad
Carlos Iribarren
Patricia Quinlan
Paul D Blanc
2020

Background: Despite well-documented case series of hypersensitivity pneumonitis (HP), epidemiological data delineating relative contributions of risk factors are sparse. To address this, we estimated HP risk in a case-referent study of occupational and nonoccupational exposures.

Methods: We recruited cases of HP by ICD-9 codes from an integrated healthcare delivery system (IHCDS) and a tertiary medical care centre. We drew referents, matched for age and sex, from the IHCDS. Participants underwent comprehensive, structured telephone interviews eliciting details of occupational and...

Smoking, occupational exposures, and idiopathic pulmonary fibrosis among Swedish construction workers

Martin Andersson
Paul D Blanc
Kjell Torén
Bengt Järvholm
2021

Background: Cigarette smoking and occupational exposures each have been reported to increase the risk of idiopathic pulmonary fibrosis (IPF), a disease previously considered of unknown origin. We investigated the risk of IPF mortality associated with combined smoking and occupational exposures.

Methods: A registry study of Swedish construction workers (N = 389,132), linked baseline smoking and occupational data with registry data on cause of death and hospital care diagnoses. Occupation was classified by the likelihood of exposure to vapors, gases,...