Evaluating the Health Risk from Secondary Sulfates in Eastern North American Regional Ambient Air Particulate Matter

Epidemiological studies of particulate matter (PM) using central area monitors have associated total PM mass, as well as certain individual components of PM, including sulfate, with adverse human health effects. However, some recent studies that used concentrated ambient particles (CAPs) or analyzed the effects of air pollution from different sources or geographic areas suggest that while some particles may be harmful, other particulate species including secondary sulfates may have negligible health effects. Toxicology studies to date also suggest that secondary sulfates pose little health risk. While studies using central-area monitors implicitly assume that all residents of the area are exposed to the same levels of pollution, newer studies find substantial health effects for those in close proximity to major roads. These latter studies recognize that although population exposure to widespread pollutants, such as total PM mass and sulfates, may be relatively uniform over a wide area, exposure to pollutants from local sources is not. While there is an emerging literature associating several adverse health effects with proximity to local pollution sources, the current database provides limited information that allows identification of specific particulate species that may cause little to no harm. In this article, we suggest that ambient secondary sulfates, and eastern North American regional air masses generally, appear to have little adverse impact on public health. This suggestion is based on evidence gleaned from eight avenues of investigation: (1) recent non-central-area monitor studies, including exposure gradient or proximity studies; (2) CAPs studies; (3) studies that examine effects related to different geographic areas or sources; (4) toxicology studies; (5) the limited number of studies that analyze existing central-area monitor data to explicitly examine the health impacts of sulfate and acidity versus PM mass; (6) “modern” area monitor studies with additional capabilities to distinguish among sources of pollution; (7) partial reinterpretation of two pivotal cohort studies; and (8) studies separating effects of secondary sulfates from those of primary metal sulfates. However, uncertainties remain regarding the role that secondary sulfates may play in ambient PM chemistry pathways leading to potentially harmful products, such as the possible effects of secondary organic aerosols that may be the product of acid catalysis of sulfur dioxide. Thus, more targeted study is needed, and some research suggestions are made in this regard.     

Social work‐generated evidence in traumatic brain injury from 1975 to 2014: A systematic scoping review

The International Network for Social Workers in Acquired Brain Injury (INSWABI) commissioned a systematic scoping review to ascertain the social work‐generated evidence base on people with traumatic brain injury (TBI) of working age. The review aimed to identify the output, impact and quality of publications authored by social workers on this topic. Study quality was evaluated through assessment frameworks drawn from the United Kingdom National Service Framework for Long‐Term Conditions. In the 40‐year period from 1975 to 2014, 115 items were published that met the search criteria (intervention studies, n = 10; observational studies, n = 52; literature reviews, n = 6; expert opinion or policy analysis, n = 39; and others, n = 8). The publications could be grouped into five major fields of practice: families, social inclusion, military, inequalities and psychological adjustment. There was a significant increase in the number of publications over each decade. Impact was demonstrated in that the great majority of publications had been cited at least once (80.6%, 103/115). Articles published in rehabilitation journals were cited significantly more often than articles published in social work journals. A significant improvement in publication quality was observed across the four decades, with the majority of studies in the last decade rated as high quality.     

Intravenous Ethanol Self-administration in C57BL/6J and DBA/2J Mice

Two strains of mice, C57BL/6J (B6) and DBA/2J (D2) were allowed to self-administer intravenous (iv) ethanol. These two strains were selected because they differ greatly in their preference for drinking ethanol solutions: 86 mice are preferrers, whereas D2 mice are avoiders of ethanol. Of interest was whether these strains would also differ in self-administration of iv ethanol when taste factors presumably do not influence consumption. Mice were trained with either 60, 75, or 90 mg/kg per infusion. Mice from both strains acquired nosepoking for all of these doses on an FR-3 schedule of reinforcement during 2-hr daily sessions. Additionally, mice in both strains acquired an equal preference for nosepoking on the side resulting in ethanol infusions, compared with the side that had no scheduled consequence, although B6 mice took somewhat more ethanol early in training than did D2 mice. Mice in both strains achieved equal levels of responding at the conclusion of training, when response rates had stabilized. A subset of animals were then tested at doses of ethanol ranging from 25 to 125 mg/kg per infusion. Although their responding tended to decrease over time regardless of changes in the unit dose of ethanol, these mice showed lower response rates for higher doses of ethanol, and less responding for saline than for ethanol. Together, these findings imply that iv ethanol has reinforcing properties in both these strains, despite the strain difference in preference for oral ethanol. Self-administration of iv ethanol in mice may prove a valuable addition to existing animal models for the study of ethanol reward.     

Correction: Self-assembled fibrillar networks comprised of a naturally-occurring cyclic peptide—LOB3

Correction for ‘Self-assembled fibrillar networks comprised of a naturally-occurring cyclic peptide—LOB3’ by M. A. Rogers et al., RSC Adv., 2016, 6, 40765–40776.

The authors regret the omission of the following conflict of interest statement.Dr Martin J. T. Reaney is the founder of, and has an equity interest in, Prairie Tide Diversified Inc. (PTD, Saskatoon, SK, Canada: previous company name is Prairie Tide Chemicals Inc.). Dr Youn Young Shim is a Market Consultant for PTD in Korea. The terms of this arrangement have been reviewed and approved by the University of Saskatchewan in accordance with its conflict of interest policies.The Royal Society of Chemistry apologises for these errors and any consequent inconvenience to authors and readers.