Determining the communicable period of SARS-CoV-2: A rapid review of the literature, March to September 2020.

IntroductionStandard testing for infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is based on RT-PCR tests, but detection of viral genetic material alone does not indicate ongoing infectious potential. The ability to isolate whole virus represents a better proxy for infectivity.AimThe objective of this study was to gain an understanding of the current literature and compare the reported periods of positive SARS-CoV-2 detection from studies that conducted RT-PCR testing in addition to experiments isolating whole virus.

Blood mercury, lead and cadmium levels and determinants of exposure among newcomer South and East Asian women of reproductive age living in Vancouver, Canada.

Background: Biomarkers of the reproductive and neuro-developmental toxicants mercury (Hg), lead (Pb) and cadmium (Cd) have been found at higher concentrations in women born outside Canada than in Canadian-born women. We measured blood Hg, Pb and Cd in women ages 19 to 45years living in greater Vancouver (Canada) within five years of their arrival from South Asia (India) or East Asia (mainland China, Hong Kong and Taiwan) and related their biomarker concentration levels with exposures and behaviors since their coming to Canada.

Methods: Participants were recruited through advertisements in relevant ethnic media, locations and groups.

Airborne Precursors Predict Maternal Serum Perfluoroalkyl Acid Concentrations.

Human exposure to persistent perfluoroalkyl acids (PFAAs), including perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), and perfluorooctanesulfonate (PFOS), can occur directly from contaminated food, water, air, and dust. However, precursors to PFAAs (PreFAAs), such as dipolyfluoroalkyl phosphates (diPAPs), fluorotelomer alcohols (FTOHs), perfluorooctyl sulfonamides (FOSAs), and sulfonamidoethanols (FOSEs), which can be biotransformed to PFAAs, may also be a source of exposure. PFAAs were analyzed in 50 maternal sera samples collected in 2007-2008 from participants in Vancouver, Canada, while PFAAs and PreFAAs were measured in matching samples of residential bedroom air collected by passive sampler and in sieved vacuum dust (<150 μm).

Modeling flight attendants' exposure to secondhand smoke in commercial aircraft: historical trends from 1955 to 1989.

Flight attendants were exposed to elevated levels of secondhand smoke (SHS) in commercial aircraft when smoking was allowed on planes. During flight attendants' working years, their occupational SHS exposure was influenced by various factors, including the prevalence of active smokers on planes, fliers' smoking behaviors, airplane flight load factors, and ventilation systems. These factors have likely changed over the past six decades and would affect SHS concentrations in commercial aircraft.

Neurodevelopmental performance among school age children in rural Guatemala is associated with prenatal and postnatal exposure to carbon monoxide, a marker for exposure to woodsmoke.

We investigated whether early life chronic exposure to woodsmoke, using personal passive 48-h carbon monoxide (CO) as an indicator, is associated with children's neurodevelopmental and behavioral performance. CO measures were collected every 3 months from 2002 to 2005 among mother-child dyads during the Randomized Exposure Study of Pollution Indoors and Respiratory Effects (RESPIRE) stove intervention trial in San Marcos, Guatemala. From March to June, 2010, study children of age 6-7 years, performed a follow-up non-verbal, culturally adapted neurodevelopmental assessment.

Simultaneous EEG, fMRI, and behavior in typical childhood absence seizures.

Purpose: Absence seizures cause transient impairment of consciousness. Typical absence seizures occur in children, and are accompanied by 3-4-Hz spike-wave discharges (SWDs) on electroencephalography (EEG). Prior EEG-functional magnetic resonance imaging (fMRI) studies of SWDs have shown a network of cortical and subcortical changes during these electrical events.