Impacts associated with the plastic polymers polycarbonate, polystyrene, polyvinyl chloride, and polybutadiene across their life cycle: A review.

Polymers are the main building blocks of plastic, with the annual global production volume of fossil carbon-based polymers reaching over 457 million metric tons in 2019 and this figure is anticipated to triple by 2060. There is potential for environmental harm and adverse human health impacts associated with plastic, its constituent polymers and the chemicals therein, at all stages of the plastic life cycle, from extraction of raw materials, production and manufacturing, consumption, through to ultimate disposal and waste management. While there have been considerable research and policy efforts in identifying and mitigating the impacts associated with problematic plastic products such as single-use plastics and hazardous chemicals in plastics, with national and/or international regulations to phase out their use, plastic polymers are often overlooked. In this review, the polymer dimension of the current knowledge on environmental release, human exposure and health impacts of plastic is discussed across the plastic life cycle, including chemicals used in production and additives commonly used to achieve the properties needed for applications for which the polymers are generally used. This review focuses on polycarbonate, polystyrene, polyvinyl chloride, and polybutadiene, four common plastic polymers made from the hazardous monomers, bisphenol, styrene, vinyl chloride and 1,3-butadiene, respectively. Potential alternative polymers, chemicals, and products are considered. Our findings emphasise the need for a whole system approach to be undertaken for effective regulation of plastics whereby the impacts of plastics are assessed with respect to their constituent polymers, chemicals, and applications and across their entire life cycle.

The plastic health map: A systematic evidence map of human health studies on plastic-associated chemicals.

BACKGROUND: The global production and use of plastic materials has increased dramatically since the 1960s and there is increasing evidence of human health impacts related to exposure to plastic-associated chemicals. There is, however, no comprehensive, regulatory, post-market monitoring for human health effects of plastic-associated chemicals or particles and it is unclear how many of these have been investigated for effects in humans, and therefore what the knowledge gaps are. OBJECTIVE: To create a systematic evidence map of peer-reviewed human studies investigating the potential effects of exposure to plastic-associated particles/chemicals on health to identify research gaps and provide recommendations for future research and regulation policy. METHODS: Medline and Embase databases were used to identify peer-reviewed primary human studies published in English from Jan 1960 - Jan 2022 that investigated relationships between exposures to included plastic-associated particles/chemicals measured and detected in bio-samples and human health outcomes. Plastic-associated particles/chemicals included are: micro and nanoplastics, due to their widespread occurrence and potential for human exposure; polymers, the main building blocks of plastic; plasticizers and flame retardants, the two most common types of plastic additives with the highest concentration ranges in plastic materials; and bisphenols and per- or polyfluoroalkyl substances, two chemical classes of known health concern that are common in plastics. We extracted metadata on the population and study characteristics (country, intergenerational, sex, age, general/special exposure risk status, study design), exposure (plastic-associated particle/chemical, multiple exposures), and health outcome measures (biochemical, physiological, and/or clinical), from which we produced the interactive database 'Plastic Health Map' and a narrative summary. RESULTS: We identified 100,949 unique articles, of which 3,587 met our inclusion criteria and were used to create a systematic evidence map. The Plastic Health Map with extracted metadata from included studies are freely available at https://osf.io/fhw7d/ and summary tables, plots and overall observations are included in this report. CONCLUSIONS: We present the first evidence map compiling human health research on a wide range of plastic-associated chemicals from several different chemical classes, in order to provide stakeholders, including researchers, regulators, and concerned individuals, with an efficient way to access published literature on the matter and determine knowledge gaps. We also provide examples of data clusters to facilitate systematic reviews and research gaps to help direct future research efforts. Extensive gaps are identified in the breadth of populations, exposures and outcomes addressed in studies of potential human health effects of plastic-associated chemicals. No studies of the human health effects of micro and/or nanoplastics were found, and no studies were found for 26/1,202 additives included in our search that are of known hazard concern and confirmed to be in active production. Few studies have addressed recent "substitution" chemicals for restricted additives such as organophosphate flame retardants, phthalate substitutes, and bisphenol analogues. We call for a paradigm shift in chemical regulation whereby new plastic chemicals are rigorously tested for safety before being introduced in consumer products, with ongoing post-introduction biomonitoring of their levels in humans and health effects throughout individuals' life span, including in old age and across generations.

Intravesical hyaluronic acid with chondroitin sulphate to prevent urinary tract infection after spinal cord injury.

CONTEXT/OBJECTIVE: Prevention of urinary tract infection (UTI) after spinal cord injury is an important goal. Intravesical hyaluronic acid with chondroitin sulphate (HA+CS) has been effective in preventing UTI in other settings. We aimed to demonstrate safety and feasibility of a standard treatment course of 7 intravesical HA+CS instillations over 12 weeks, in patients with acute (Arm A) and chronic (Arm B) spinal cord injury (SCI). DESIGN: Follow-up of adverse events, quality of life bladder management difficulty (BMD) and bladder complication (BC) T-scores at baseline (Arm B only), 12 and 24 weeks, and symptomatic urinary tract infection (UTI). RESULTS: Of 33 and 14 individuals screened, 2 and 8 participants were recruited to the study for Arm A and Arm B respectively. Of the 10 participants, 8 completed all 7 instillations. HA+CS commonly caused cloudy urine with urinary sediment which was mild and short-lived. In Arm B, a mean reduction in BMD and BC T-scores was observed from baseline (57.3 and 54.4 respectively), of 6.8 and 4.3 at 12 weeks and 1.6 and 2.8 at 24 weeks, respectively. Four participants with a history of frequent UTI in the prior 12 months did not have UTI in the 24 weeks of the study. CONCLUSIONS: HA+CS was well tolerated. Recruitment was more difficult in early acute SCI; participants with chronic SCI were highly motivated to reduce UTI and manage self-administration without difficulty. Larger case-control or randomized controlled trials in patients with neurogenic bladder from SCI are warranted. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT03945110.

A scoping review protocol on in vivo human plastic exposure and health impacts.

BACKGROUND: Global plastic production has increased exponentially since the 1960s, with more than 6300 million metric tons of plastic waste generated to date. Studies have found a range of human health outcomes associated with exposure to plastic chemicals. However, only a fraction of plastic chemicals used have been studied in vivo, and then often in animals, for acute toxicological effects. With many questions still unanswered about how long-term exposure to plastic impacts human health, there is an urgent need to map human in vivo research conducted to date, casting a broad net by searching terms for a comprehensive suite of plastic chemical exposures and the widest range of health domains. METHODS: This protocol describes a scoping review that will follow the recommended framework outlined in the 2017 Guidance for the Conduct of Joanna Briggs Institute (JBI) Scoping Reviews, to be reported in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) Checklist. A literature search of primary clinical studies in English from 1960 onwards will be conducted in MEDLINE (Ovid) and EMBASE (Ovid) databases. References eligible for inclusion will be identified through a quality-controlled, multi-level screening process. Extracted data will be presented in diagrammatic and tabular form, with a narrative summary addressing the review questions. DISCUSSION: This scoping review will comprehensively map the primary research undertaken to date on plastic exposure and human health. Secondary outputs will include extensive databases on plastic chemicals and human health outcomes/impacts. SYSTEMATIC REVIEW REGISTRATION: Open Science Framework (OSF)-Standard Pre-Data Collection Registration, https://archive.org/details/osf-registrations-gbxps-v1 , https://doi.org/10.17605/OSF.IO/GBXPS.

Barriers and facilitators to optimising inpatient bladder management after spinal cord injury.

STUDY DESIGN: Qualitative survey. OBJECTIVES: Examine clinicians' perspectives on adherence to published evidence-based guidelines and clinician-perceived barriers, and facilitators to optimising inpatient bladder management within one Spinal Cord Injury (SCI) service. SETTING: Surgical Hospital (acute care) and SCI Unit (sub-acute, rehabilitation) in Western Australia (WA). METHODS: Clinicians reviewed an 'Evidence Matrix' summarising published clinical practice guidelines and recommendations for SCI bladder management. Focus groups examined the extent to which current practice adhered to recommendations and identified perceived barriers and facilitators to optimal management. Data were analysed thematically using a deductive approach. RESULTS: Current management closely mirrors published recommendations. Key facilitators included long-standing prioritisation of rapid progression from urethral indwelling (IDC) to a 6 hourly intermittent catheterisation (IC) protocol; regular competency audits of catheterisation technique; and a Spinal Urology Clinical Nurse Consultant (CNC) position. Barriers included limited resources/staffing; restricted access to Neuro-urology consultation; inter-disciplinary communication gaps; and delays in determining and implementing long-term bladder management. CONCLUSIONS: Inpatient SCI bladder care in WA closely emulates published evidence, although adherence at other sites may reveal different practices. Bladder management was found to have been facilitated by a strong culture of practice led by Neuro-urologists, informed by evidence and embraced by Senior Clinicians. Further reduction in duration of initial IDC, provision of early and ongoing Neuro-urology consultations as part of standard care, increased interdisciplinary communication and dedicated SCI Urology theatre lists would further optimise management.

Early urinary tract infection after spinal cord injury: a retrospective inpatient cohort study.

STUDY DESIGN: Retrospective audit. OBJECTIVES: Examine factors associated with urinary tract infection (UTI), UTI incidence and impact on hospital length of stay (LOS) in new, inpatient adult traumatic spinal cord injury (SCI). SETTING: Western Australian Hospitals managing SCI patients. METHODS: Data on UTIs, bladder management and LOS were obtained from hospital databases and medical records over 26 months. Adherence to staff-administered intermittent catheterisation (staff-IC) was determined from fluid balance charts. RESULTS: Across the cohort (n = 70) UTI rate was 1.1 starts/100 days; UTI by multi-resistant organisms 0.1/100 days. Having ≥1 UTIs compared with none and longer duration of initial urethral indwelling catheterisation (IDC) were associated with longer LOS (p-values < 0.001). For patients with ≥1 UTIs (n = 43/70), longer duration of initial IDC was associated with shorter time to first UTI (1 standard deviation longer [SD, 45.0 days], hazard ratio (HR): 0.7, 95% confidence interval [CI] 0.5-1.0, p-value 0.044). In turn, shorter time to first UTI was associated with higher UTI rate (1 SD shorter [30.7 days], rate ratio (RR): 1.32, 95%CI 1.0-1.7, p-value 0.039). During staff-IC periods (n = 38/70), protocols were followed (85.7% ≤ 6 h apart, 96.1% < 8 h), but 26% of IC volumes exceeded 500 mL; occasional volumes > 800 mL and interruptions requiring temporary IDC were associated with higher UTI rates the following week (odds ratios (ORs): 1.6, 95%CI 1.1-2.3, p-value 0.009; and 3.9, 95%CI 2.6-5.9, p-value < 0.001 respectively). CONCLUSIONS: Reducing initial IDC duration and limiting staff-IC volumes could be investigated to possibly reduce inpatient UTIs and LOS. SPONSORSHIP: None.