Health effects of exposure to chlorination by-products in swimming pools

Concerns have been raised regarding the potential negative effects on human health of water disinfectants used in swimming pools. Among the disinfection options, the approaches using chlorine-based products have been typically preferred. Chlorine readily reacts with natural organic matter that are introduced in the water mainly through the bathers, leading to the formation of potentially harmful chlorination by-products (CBPs). The formation of CBPs is of particular concern since some have been epidemiologically associated with the development of various clinical manifestations. The higher the concentration of volatile CBPs in the water, the higher their concentration in the air above the pool, and different routes of exposure to chemicals in swimming pools (water ingestion, skin absorption, and inhalation) contribute to the individual exposome. Some CBPs may affect the respiratory and skin health of those who stay indoor for long periods, such as swimming instructors, pool staff, and competitive swimmers. Whether those who use chlorinated pools as customers, particularly children, may also be affected has been a matter of debate. In this article, we discuss the current evidence regarding the health effects of both acute and chronic exposures in different populations (work-related exposures, intensive sports, and recreational attendance) and identify the main recommendations and unmet needs for research in this area.     

Molecular survey of parasites in introduced Pelophylax perezi (Ranidae) water frogs in the Azores

Water frogs, Pelophylax perezi, that are introduced in the Azores, were screened for parasites using PCR primers known to amplify Apicomplexa parasites, and using nematode-specific primers. With the former, three different organisms were detected: Hepatozoon, a trichodinid protozoan ciliate and a possible Stramenopile. Using the latter set of primers, a single unknown spirurid nematode was also detected. Phylogenetic analyses indicate that Hepatozoon detected within amphibian hosts appear to form a clade, although relationships of these parasites do not match the vertebrate intermediate host phylogeny. Regarding the possible Stramenopile, it is unclear whether this organism was actually present on the amphibian or in the water on the surface of the tissue sample. Our findings highlight that many different organisms can be detected with these primers and that they can be used to screen introduced host populations to detect parasites that have been brought with them.     

Six weeks of aerobic training improves VO2max and MLSS but does not improve the time to fatigue at the MLSS

The purpose of this study was to investigate the effects of a 6-week aerobic training period on the time to fatigue (t _lim) during exercise performed at the maximal lactate steady state (MLSS). Thirteen untrained male subjects (TG; age 22.5 ± 2.4 years, body mass 72.9 ± 6.7 kg and VO_2max 44.9 ± 4.8 mL kg^?1 min^?1) performed a cycle ergometer test until fatigue at the MLSS power output before and after 6 weeks of aerobic training. A group of eight control subjects (CG; age 25.1 ± 2.4 years, body mass 70.1 ± 9.8 kg and VO_2max 45.2 ± 4.1 mL kg^?1 min^?1) also performed the two tests but did not train during the 6-week period. There were no differences between the groups with respect to the VO_2max or MLSS power output (MLSSw) before the treatment period. The VO_2max and the MLSSw of the TG increased by 11.2 ± 7.2 % (pre-treatment = 44.9 ± 4.8 vs. post-treatment = 49.8 ± 4.5 mL kg^?1 min^?1) and 14.7 ± 8.9 % (pre-treatment = 150 ± 27 vs. post-treatment = 171 ± 26 W), respectively, after 6 weeks of training. The results of the CG were unchanged. There were no differences in t _lim between the groups or within groups before and after training. Six weeks of aerobic training increases MLSSw and VO_2max, but it does not alter the t _lim at the MLSS.     

Impaired performance of women with patellofemoral pain during functional tests

ObjectiveTo compare the performance, reliability, and validity of functional tests between women with and without patellofemoral pain.MethodsTwenty women with a diagnosis of patellofemoral pain between 18 and 40 years of age and 20 age-matched pain-free controls participated in the study. All participants performed a set of five function tests: sitting-rising test, sit-to-stand in 30 seconds, stair-climb test, stair descent test, and six-minute step test. To investigate reliability, participants were assessed on two different days, seven days apart, by two independent investigators blinded to the results of the other investigator. Validity was evaluated through associations with the results on the Anterior Knee Pain Scale.ResultsPerformance in the tests was worse in women with patellofemoral pain than in the control group for the sit-to-stand in 30 seconds (mean difference [MD] 3.4reps; 95%CI: 0.4, 6.4), stair-climb test (MD: 0.36 s; 95%CI: 0.1, 0.63), and six-minute step test (MD: 45reps; 95%CI: 20, 70). No differences were observed for the sitting-rising and stair descent tests. All tests in both groups showed moderate to excellent intra- and inter-rater reliability (intraclass correlation coefficients: 0.61 to 0.91 and 0.72 to 0.96, respectively). Finally, only the results on the sit-to-stand in 30 seconds test correlated with the Anterior Knee Pain Scale (r = 0.44, p = 0.047) in the patellofemoral pain group.ConclusionWomen with patellofemoral pain present lower performance on some functional tests. Functional tests are reliable in patients with patellofemoral pain, although they are not associated with the results on the Anterior Knee Pain Scale self-questionnaire.     

The Strongest Correlates of PTSD for Firefighters: Number,Recency, Frequency,or Perceived Threat of Traumatic Events?

Firefighters experience a wide range of traumatic events while on duty and are at risk to develop psychopathology and posttraumatic stress disorder (PTSD). According to cognitive models, the person's interpretation of the traumatic event is responsible for the development of PTSD rather than the traumatic event itself. This cross‐sectional study aimed to explore the contribution of perceived threat to explain PTSD symptoms in Portuguese firefighters, after adjusting for potential confounding factors. A sample of 397 firefighters completed self‐report measures of exposure to traumatic events, psychopathology, and PTSD. Perceived threat explained unique variance in PTSD symptoms, R² = .40, ΔR² = .02, F(10, 367) = 24.55, p < .001, Cohen's f² =.03, after adjusting for psychopathology, number, recency, and frequency of the events, and other potential confounding variables. The association between psychopathology and PTSD was also moderated by perceived threat, R² = .43, ΔR² = .03, F(11, 366) = 25.33, p < .001, Cohen's f² =.05. Firefighters may benefit from interventions that focus on perceived threat to prevent PTSD symptoms.     

Custo-efetividade do Stent Farmacológico na Intervenção Coronariana Percutânea no SUS

BackgroundThe use of drug-eluting stents (DESs), compared with bare-metal stents (BMSs), in percutaneous coronary intervention (PCI) has reduced the rate of restenosis, without an impact on mortality but with an increase in costs. Medical literature lacks randomized studies that economically compare these 2 stent types within the reality of the Brazilian Unified Public Health System (SUS).ObjectiveTo estimate the incremental cost-effectiveness ratio (ICER) between DES and BMS in SUS patients with single-vessel coronary artery disease.MethodsOver a 3-year period, patients with symptomatic single-vessel coronary artery disease were randomized in a 1:2 ratio to receive a DES or BMS during PCI, with a 1-year clinical follow-up. The evaluation included in-stent restenosis (ISR), target lesion revascularization (TLR), major adverse events, and cost-effectiveness for each group. P-values <0.05 were considered significant.ResultsIn the DES group, of 74 patients (96.1%) who completed the follow-up, 1 developed ISR (1.4%), 1 had TLR (1.4%), and 1 died (1.4%), with no cases of thrombosis. In the BMS group, of 141 patients (91.5%), ISR occurred in 14 (10.1%), TLR in 10 (7.3%), death in 3 (2.1%), and thrombosis in 1 (0.74%). In the economic analysis, the cost of the procedure was R$ 5,722.21 in the DES group and R$ 4,085.21 in the BMS group. The effectiveness by ISR and TLR was 8.7% for DES and 5.9% for BMS, with an ICER of R$ 18,816.09 and R$ 27,745.76, respectively.ConclusionsIn the SUS, DESs were cost-effective in accordance with the cost-effectiveness threshold recommended by the World Health Organization (Arq Bras Cardiol. 2020; 115(1):80-89)