Toxicity of particulate emissions from residential biomass combustion: An overview of in vitro studies using cell models

This article aims to critically review the current state of knowledge on in vitro toxicological assessments of particulate emissions from residential biomass heating systems. The review covers various aspects of particulate matter (PM) toxicity, including oxidative stress, inflammation, genotoxicity, and cytotoxicity, all of which have important implications for understanding the development of diseases. Studies in this field have highlighted the different mechanisms that biomass combustion particles activate, which vary depending on the combustion appliances and fuels. In general, particles from conventional combustion appliances are more potent in inducing cytotoxicity, DNA damage, inflammatory responses, and oxidative stress than those from modern appliances. The sensitivity of different cell lines to the toxic effects of biomass combustion particles is also influenced by cell type and culture conditions. One of the main challenges in this field is the considerable variation in sampling strategies, sample processing, experimental conditions, assays, and extraction techniques used in biomass burning PM studies. Advanced culture systems, such as co-cultures and air-liquid interface exposures, can provide more accurate insights into the effects of biomass combustion particles compared to simpler submerged monocultures. This review provides critical insights into the complex field of toxicity from residential biomass combustion emissions, underscoring the importance of continued research and standardisation of methodologies to better understand the associated health hazards and to inform targeted interventions.

GET-UP Trial 1-year results: long-term impact of an early mobilization protocol on functional performance after surgery for chronic subdural hematoma

OBJECTIVE

Evidence on timing for mobilization after chronic subdural hematoma (cSDH) surgery is heterogeneous, and practices differ considerably among neurosurgical centers. The Impact of an Early Out-of-Bed Paradigm in Postoperative Outcomes of Chronic Subdural Hematomas: GET-UP Randomized Prospective Trial (GET-UP Trial) is a randomized clinical trial comparing a postoperative early mobilization protocol to bed rest. Previously reported results at clinical discharge and 1 month after surgery indicated a decreased risk of medical complications in the early mobilization group. Herein, the authors report outcomes at the 1-year follow-up.

METHODS

The GET-UP Trial is a prospective, randomized, unicentric, open-label study with an intention-to-treat primary analysis designed to evaluate the impact of an early mobilization protocol after burr hole craniostomy for cSDH on the occurrence of medical complications and functional outcomes. Between January 2019 and August 2021, a total of 208 patients were recruited and randomized to either an early mobilization group, in which patients began elevation of the head of the bed within the first 12 hours after surgery, or to a bed rest group, in which patients remained recumbent for 48 hours. Outcomes assessed at the 1-year follow-up included functional status as measured by the Glasgow Outcome Scale-Extended (GOSE) and repeat surgery for hematoma recurrence (surgical recurrence).

RESULTS

A total of 203 patients completed 1 year of follow-up: 101 in the bed rest group and 102 in the early mobilization group. No significant baseline pre-randomization clinical differences were observed between the two management groups. At 1 year after surgery, a favorable functional outcome, defined as a GOSE score ≥ 5, was observed in 59 patients (58.4%) in the bed rest group and 78 (76.5%) in the early mobilization group (p = 0.006). Death occurred in 25 patients (24.8%) in the bed rest group and 16 (15.7%) in the early mobilization group (p = 0.108). Surgical recurrence was noted in 6 patients (5.9%) in the bed rest group and 7 (6.9%) in the early mobilization group (p = 0.788). Multivariate analysis showed an independent association between early mobilization and an increase in favorable functional outcomes (OR 2.006, 95% CI 1.076-3.739, p = 0.028).

CONCLUSIONS

The GET-UP Trial is the first randomized clinical trial assessing the impact of mobilization strategies on medical complications after burr hole craniostomy for cSDH. Regarding functional results 1 year after surgery, early mobilization was associated with an improvement in functional outcomes without an increase in surgical recurrence. These findings support the preference for an early mobilization protocol in cSDH patients over mandatory bed rest strategies.

The role of snow in scavenging aerosol particles: A physical-chemical characterization

The below cloud scavenging of aerosols by snow has been analysed in León (NW Spain). Six snow events were registered over the course of one year of study. Ultrafine and accumulation aerosol particles were measured using a scanning mobility particle sizer spectrometer, while hydrometeors were characterized using a disdrometer. Furthermore, the chemical composition of the melted snow-water samples (soluble and insoluble fractions) was analysed. The scavenging coefficient (λ) showed a great variability among events. An effective washing of particles was observed during the first 30 min of snowfall. The mean change in the scavenging efficiency (%ΔC) of particle number concentration (PNC) and λ coefficient during this time interval were: i) nucleation mode: 36.3 % and 3.02 · 10-4 s-1; ii) Aitken mode: 30.4 % and 2.37 · 10-4 s-1 and iii) accumulation mode: 22.4 % and 1.77 · 10-4 s-1. The range of particle sizes that is less efficiently scavenged by snowfall was observed between 400 and 600 nm. When analyzing the whole snow event, an increase of PNC was observed. Two possible explanations underlie this behaviour: it could be caused by changes in air masses or by the resuspension of aerosol particles scavenged by snowflakes upon reaching the ground. A clear relationship was observed between Ca2+, SO42- and NO3- concentrations of aerosol particles before the snow event and the concentrations registered in the melted snow-water. The largest and smallest changes in aerosol number concentrations were caused by snowflakes of 3 and 6 mm in diameter, respectively. The particle size distributions (PSD) were fitted to log-normal distributions and the parameters were compared before and after snowfall.

Biological Impact of Organic Extracts from Urban-Air Particulate Matter: An In Vitro Study of Cytotoxic and Metabolic Effects in Lung Cells

Atmospheric particulate matter (PM) with diameters below 10 µm (PM10) may enter the lungs through inhalation and are linked to various negative health consequences. Emergent evidence emphasizes the significance of cell metabolism as a sensitive target of PM exposure. However, the current understanding of the relationship between PM composition, conventional toxicity measures, and the rewiring of intracellular metabolic processes remains limited. In this work, PM10 sampled at a residential area (urban background, UB) and a traffic-impacted location (roadside, RS) of a Portuguese city was comprehensively characterized in terms of polycyclic aromatic hydrocarbons and plasticizers. Epithelial lung cells (A549) were then exposed for 72 h to PM10 organic extracts and different biological outcomes were assessed. UB and RS PM10 extracts dose-dependently decreased cell viability, induced reactive oxygen species (ROS), decreased mitochondrial membrane potential, caused cell cycle arrest at the G0/G1 phase, and modulated the intracellular metabolic profile. Interestingly, the RS sample, richer in particularly toxic PAHs and plasticizers, had a greater metabolic impact than the UB extract. Changes comprised significant increases in glutathione, reflecting activation of antioxidant defences to counterbalance ROS production, together with increases in lactate, NAD+, and ATP, which suggest stimulation of glycolytic energy production, possibly to compensate for reduced mitochondrial activity. Furthermore, a number of other metabolic variations hinted at changes in membrane turnover and TCA cycle dynamics, which represent novel clues on potential PM10 biological effects.

Residential combustion of coal: Effect of the fuel and combustion stage on emissions

Worldwide coal is still used for household heating purposes not only because it is available and cheap but also due to behavioural issues. Regional variability in fuels and combustion appliances make accurate emission estimates from this source hard to achieve. In the present study, gaseous (CO, VOCs, SO2 and NOX) and particulate matter (TSP) emission factors (EFs) were determined for Spanish household coal combustion covering three commercial coals and distinct combustion stages and mimicking usage patterns in real households. TSP samples were analysed to determine water-soluble inorganic ions, metal(loid)s, and organic and elemental carbon (OC and EC). Additionally, the morphology of the emitted particles was also characterised. CO (3.43-169 g kg-1), NOX (1.29-6.00 g kg-1) and SO2 (8.96-22.3 g kg-1) EFs showed no trend regarding the combustion stage or coal type tested. On the other hand, VOC, TSP and EC EFs were higher for the ignition/devolatilisation combustion stage, regardless of the fuel tested. TSP EFs (0.085-1.08 g kg-1) increased with increasing coal volatile matter while the opposite trend was recorded for VOC emissions (0.045-3.39 gC kg-1). TSP carbonaceous matter was dominated by EC while OC represented a small fraction of the particulate mass emitted (less than 8 %wt.). Inorganic compounds composed an important fraction of the TSP samples. Sulphate particulate mass fractions (8.66-22.9 %wt.) appeared to increase with coal S-content. Coal combustion released particles with diverse morphologies, including silicate-rich particles, ferro- and glassy-spheres. This study provides novel emission factors to update emission inventories of residential coal combustion. Additionally, detailed chemical profiles were obtained for source apportionment.

Impact of an early mobilization protocol on the reduction of medical complications after surgery for chronic subdural hematoma: the GET-UP Trial

OBJECTIVE

Timing of mobilization after chronic subdural hematoma (cSDH) surgery is highly heterogeneous among neurosurgical centers. Past studies have suggested that early mobilization may reduce medical complications without increasing recurrence, but evidence remains scarce. The purpose of this study was to compare an early mobilization protocol with a 48-hour bed rest practice, with a focus on the occurrence of medical complications.

METHODS

The GET-UP Trial is a prospective, randomized, unicentric, open-label study with an intention-to-treat primary analysis designed to evaluate the impact of an early mobilization protocol after burr hole craniostomy for cSDH on the occurrence of medical complications and functional outcomes. A total of 208 patients were recruited and randomly assigned to either an early mobilization group where they began head-of-bed elevation within the first 12 hours after surgery and proceeded to sedestation, orthostatism, and/or walking as rapidly as tolerated, or to a bed rest group where they remained recumbent with a head-of-bed angle inferior to 30° for 48 hours after surgery. The primary outcome was the occurrence of a medical complication (defined as either an infection, seizure, or thrombotic event) after surgery and until clinical discharge. Secondary outcomes included length of stay measured from randomization to clinical discharge, surgical hematoma recurrence at clinical discharge and 1 month after surgery, and Glasgow Outcome Scale-Extended (GOSE) assessment at clinical discharge and 1 month after surgery.

RESULTS

A total of 104 patients were randomly assigned to each group. No significant baseline clinical differences were observed before randomization. The primary outcome occurred in 36 (34.6%) patients included in the bed rest group and 20 (19.2%) in the early mobilization group (p = 0.012). At 1 month after surgery, a favorable functional outcome (defined as GOSE score ≥ 5) was observed in 75 (72.1%) patients in the bed rest group and 85 (81.7%) in the early mobilization group (p = 0.100). Surgical recurrence occurred in 5 (4.8%) patients in the bed rest group and 8 (7.7%) in the early mobilization group (p = 0.390).

CONCLUSIONS

The GET-UP Trial is the first randomized clinical trial to assess the impact of mobilization strategies on medical complications after burr hole craniostomy for cSDH. Early mobilization was associated with a reduction in medical complications without a significant effect on surgical recurrence, compared with a 48-hour bed rest protocol.

Assessing the chemical composition, potential toxicity and cancer risk of airborne fine particulate matter (PM2.5) near a petrochemical industrial area

In the vicinity of a petrochemical industrial region in São Paulo, Brazil, PM_2.5-bound organic carbon (OC), elemental carbon (EC), polycyclic aromatic hydrocarbons (PAHs), nitro-PAHs, oxy-PAHs, hopanes, and inorganic species were evaluated. Oxidative potential (OP), burden (OB), and Alivibrio fischeri bioluminescence inhibition (AFBIA) assays were conducted to determine the potential health effects of exposure to these compounds. The PM_2.5 mean concentration was 32.0±18.2µgm^-3, and benzo (a)pyrene was found to exceed recommended levels by at least four times. Secondary sources and vehicular emissions were indicated by nitro-PAHs, oxy-PAHs, and inorganic species. The OP and OB results revealed that secondary compounds favored antioxidant depletion. The AFBIA results showed that 64% of the samples were toxic. These findings emphasize the need to reduce the exposure risk and take measures to protect human health.

Emission factors for a biofuel impacted fleet in south America's largest metropolitan area

The Metropolitan Area of São Paulo (MASP) is among the largest urban areas in the Southern Hemisphere. Vehicular emissions are of great concern in metropolitan areas and MASP is unique due to the use of biofuels on a large scale (sugar-cane ethanol and biodiesel). In this work, tunnel measurements were employed to assess vehicle emissions and to calculate emission factors (EFs) for heavy-duty and light-duty vehicles (HDVs and LDVs). The EFs were determined for particulate matter (PM) and its chemical compounds. The EFs obtained for 2018 were compared with previous tunnel experiments performed in the same area. An overall trend of reduction of fine and coarse PM, organic carbon (OC), and elemental carbon (EC) EFs for both LDVs and HDVs was observed if compared to those observed in past years, suggesting the effectiveness of vehicular emissions control policies implemented in Brazil. A predominance of Fe, Cu, Al, and Ba metals emission was observed for the LDV fleet in the fine fraction. Cu presented higher emissions than two decades ago, which was associated with the increased use of ethanol fuel in the region. For HDVs, Zn and Pb were mostly emitted in the fine mode and were linked with lubricating oil emissions from diesel vehicles. A predominance in the emission of three- and four-ring polycyclic aromatic hydrocarbons (PAHs) for HDVs and five-ring PAHs for LDVs agreed with what was observed in previous studies. The use of biofuels may explain the lower PAH emissions for LDVs (including carcinogenic BaP) compared to those observed in other countries. The tendency observed was that LDVs emit higher amounts of carcinogenic species. The use of these real EFs in air quality modeling resulted in more accurate simulations of PM concentrations, showing the importance of updating data with real-world measurements.

Exhaust emissions of gaseous and particle size-segregated water-soluble organic compounds from diesel-biodiesel blends

This study assessed the emissions of gaseous pollutants and particle size distributed water-soluble organics (WSO) from a diesel vehicle fuelled with ultralow sulphur diesel (B0) and 10 (B10), 20 (B20), and 30% (B30) biodiesel blends in a chassis dynamometer tested under transient mode. Particulate emission sampling was carried out in an ultraviolet (UV) test chamber using a 10-stage impactor. Samples were grouped into three size fractions and analysed by gas chromatography-mass spectrometry. Increasing the biofuel ratio up to 30% in the fuel reduced WSO emissions by 20.9% in comparison with conventional diesel. Organic acids accounted for 82-89% of WSO in all tested fuels. Dicarboxylic acids were the most abundant compound class, followed by hydroxy, aromatic, and linear alkanoic acids. Correlations between compounds demonstrated that adding biodiesel to diesel fuel reduces the emissions of nitrogen oxides (NOx), benzene, toluene, ethylbenzene and xylenes (BTEX), methane (CH4), total and nonmethane hydrocarbons (THC and NMHC), and dicarboxylic and hydroxy acids, but increases emissions of carbon dioxide (CO2) and alkanoic and aromatic acids. Emissions of dicarboxylic and hydroxy acids were strongly correlated with the biodiesel content. WSO emissions of coarse and fine (1.0-10 μm) particles decreased with the increasing biofuel content in fuel blend. The total share of ultrafine (0.18-1.0 μm) and nanoparticles (< 0.18 μm) increased in WSOs emissions from B20 and B30 blends, when compared with petrodiesel. The biodiesel content also affected the chemical profile of WSO size fractions.

Source apportionment of PM2.5 before and after COVID-19 lockdown in an urban-industrial area of the Lisbon metropolitan area, Portugal

The lockdowns held due to the COVID-19 pandemic conducted to changes in air quality. This study aimed to understand the variability of PM_2.5 levels and composition in an urban-industrial area of the Lisbon Metropolitan Area and to identify the contribution of the different sources. The composition of PM_2.5 was assessed for 24 elements (by PIXE), secondary inorganic ions and black carbon. The PM_2.5 mean concentration for the period (December 2019 to November 2020) was 13 ± 11 μg.m^-3. The most abundant species in PM_2.5 were BC (19.9%), SO₄ ^2- (15.4%), NO₃ ^- (11.6%) and NH₄ ⁺ (5.3%). The impact of the restrictions imposed by the COVID-19 pandemic on the PM levels was found by comparison with the previous six years. The concentrations of all the PM_2.5 components, except Al, Ba, Ca, Si and SO₄ ^2-, were significantly higher in the winter/pre-confinement than in post-confinement period. A total of seven sources were identified by Positive Matrix Factorisation (PMF): soil, secondary sulphate, fuel-oil combustion, sea, vehicle non-exhaust, vehicle exhaust, and industry. Sources were greatly influenced by the restrictions imposed by the COVID-19 pandemic, with vehicle exhaust showing the sharpest decrease. Secondary sulphate predominated in summer/post-confinement. PM_2.5 levels and composition also varied with the types of air mass trajectories.

PM2.5 chemical composition and health risks by inhalation near a chemical complex

Particulate matter (PM_2.5) samples were collected in the vicinity of an industrial chemical pole and analysed for organic and elemental carbon (OC and EC), 47 trace elements and around 150 organic constituents. On average, OC and EC accounted for 25.2% and 11.4% of the PM_2.5 mass, respectively. Organic compounds comprised polycyclic aromatic hydrocarbons (PAHs), alkylated PAHs, anhydrosugars, phenolics, aromatic ketones, glycerol derivatives, aliphatic alcohols, sterols, and carboxyl groups, including aromatic, carboxylic and dicarboxylic acids. Enrichment factors > 100 were obtained for Pb, Cd, Zn, Cu, Sn, B, Se, Bi, Sb and Mo, showing the contribution of industrial emissions and nearby major roads. Principal component analysis revealed that vehicle, industrial and biomass burning emissions accounted for 66%, 11% and 9%, respectively, of the total PM_2.5-bound PAHs. Some of the detected organic constituents are likely associated with plasticiser ingredients and thermal stabilisers used in the manufacture of PVC and other plastics in the industrial complex. Photooxidation products of both anthropogenic (e.g., toluene) and biogenic (e.g., isoprene and pinenes) precursors were also observed. It was estimated that biomass burning accounted for 13.8% of the PM_2.5 concentrations and that secondary OC represented 37.6% of the total OC. The lifetime cancer risk from inhalation exposure to PM_2.5-bound PAHs was found to be negligible, but it exceeded the threshold of 10^-6 for metal(loi)s, mainly due to Cr and As.

Particulate matter fingerprints in biofuel impacted tunnels in South America's largest metropolitan area

This study characterized the chemical composition of particulate matter (PM) from light- (LDV) and heavy-duty (HDV) vehicles based on two traffic tunnel samplings carried out in the megacity of São Paulo (Brazil), which has >7 million vehicles and intense biofuel use. The samples were collected with high-volume samplers and analyzed using chemical characterization techniques (ion and gas chromatography, thermal-optical analysis, and inductively coupled plasma mass spectroscopy). Chemical source profiles (%) were calculated based on the measurements performed inside and outside the tunnels. Identifying a high abundance of Fe and Cu for traffic-related PM in the LDV-impacted tunnel was possible, linked with the emission of vehicles powered by ethanol and gasohol (gasoline and ethanol blend). We calculated diagnostic ratios (e.g., EC/Cu, Fe/Cu, pyrene/benzo[a]pyrene, pyrene/benzo[b]fluoranthene, and fluoranthene/benzo[b]fluoranthene) characteristic of fuel exhausts (diesel/biodiesel and ethanol/gasohol), allowing their use in the assessment of the temporal variation of the fuel type used in urban sites. Element diagnostic ratios (Cu/Sb and Fe/Cu) pointed to the predominance of LDVs exhaust-related copper and can differentiate LDVs exhaust from brake wear emissions. The carbonaceous fraction EC3 was suggested as an HDV emission tracer. A higher total polycyclic aromatic hydrocarbons (PAHs) fraction of traffic-related PM_2.5 was observed in the HDV-impacted tunnel, with a predominance of diesel-related pyrene and fluoranthene, as well as higher oxy-PAHs (e.g., 9,10-anthraquinone, associated with biodiesel blends) abundances. However, carcinogenic species presented higher abundances for the LDV-impacted tunnel (e.g., benzo[a]pyrene). These findings highlighted the impact of biofuels on the characteristic ratios of chemical species and pointed to possible markers for LDVs and HDVs exhausts.

A service evaluation of joint working across sectors to promote self-administration of subcutaneous systemic anti-cancer therapy in breast cancer patients

Introduction

Trastuzumab(T) is a humanized monoclonal antibody used in the treatment of HER2-positive breast cancer and is available as a subcutaneous(sc) formulation thereby allowing short and convenient administration. A lack of trained nurses to administer T at home and/or train patients at home to self-administer, together with challenges in maintaining cold-chain delivery have impeded uptake of home administration.1,2 In order to support patients’ ability to self-administer T at home, we have implemented an educational programme that includes nurse-led training, education material, support apps and follow-up telephone clinics. Home delivery of pre-filled syringes was enabled in collaboration with commercial providers for aseptics and logistic.

Aim

The aim of this service evaluation was to evaluate the utility of this programme from the patients’ perspective and to assess patient satisfaction and impact on quality of life (QOL).

Methods

A previously validated Self-Injection Assessment Questionnaire (SIAQ)3 was modified to assess patient satisfaction, perceptions and impact of the programme. Patients who had agreed to enrol on the ‘self-administration’ scheme, were asked to complete the questionnaire at baseline, at the third training session and at the second self-administered dose. Approval from a Research Ethics Committee is not required for this service evaluation.

Results

All 14 patients offered the questionnaire responded to all questions. The median age was 58 years old (age range 43-76), 11 patients were Caucasian, 2 were Asian and one was African/Caribbean. The average distance from their home address to hospital was 10.1 miles (range 4-19). Following completion of the one-to-one nurse training there was an improvement in patient confidence to self-administer sc. T. No differences in ‘feeling in control of their treatment’ or ‘satisfaction of attending hospital appointments’ were noted. Of the 11 patients who reached the self-administration stage, 10 reported that they felt ‘very confident’ and 8 reported that it was ‘very easy’ to give themselves the injection. All patients rated themselves ‘very satisfied’ with self-administration and reported that the nurse training programme helped them to be more confident. 10 patients reported that the App and written information was useful as well as the pre- and post- administration telephone clinics. All patients reported that the self-administration programme had a positive impact on their QOL by reducing the number of hospital visits. In the first 4 months of self-administration each patient reduced their hospital attendance by an average of 8 appointments (median=8) equating to 10 hours of time that would have been spent at hospital.

Discussion/Conclusion

The subcutaneous T self-administration programme was well received by patients. The nurse training sessions and supportive materials enabled patients to feel more confident about self-administration with no reported incidents or adverse events. This led to fewer hospital visits and improved QOL. This programme was critically dependent on the services of a commercial compounder and homecare provider, emphasizing the importance of joint working between the NHS and commercial sector. Evaluation of this programme will continue and will include other agents, including Phesgo® (sc trastuzumab and pertuzumab) which have more patients and will improve the reliability of the results.

References

1. Tjalma, W., Huizing, M., Papadimitriou, K. The smooth and bumpy road of trastuzumab administration: from intravenous (IV) in a hospital to subcutaneous (SC) at home. Facts Views Vis Obgyn, 2017;9(1):51-55.

2. Grady, PA, Gough, LL. Self-management: a comprehensive approach to management of chronic conditions. American Journal of Public Health 2014; 104(8):e25-31. doi:10.2105/AJPH.2014.302041

3. Keininger D, Coteur G. Assessment of self-injection experience in patients with rheumatoid arthritis: psychometric validation of the Self-Injection Assessment Questionnaire (SIAQ). Health Qual Life Outcomes. 2011;9:2. doi:10.1186/1477-7525-9-2

Children's exposure to size-fractioned particulate matter: Chemical composition and internal dose

The health effects of the particulate matter (PM) depend not only on its aerodynamic diameter (AD) and chemical composition, but also on the time activity pattern of the individuals and on their age. The main objective of this work was to assess the exposure of children to aerosol particles by using personal instruments, to study the particle size and composition of the inhaled PM, and to estimate their transport and deposition into the human respiratory tract (HRT). The average daily PM2.5 exposure was 19 μg/m³ and the size fractions with the greatest contribution to PM2.5 concentrations were 1 < AD <2.5 μm and AD <0.25 μm. Results indicated a contribution of 9% from the mineral aerosol, 7.2% from anthropogenic sulphate, 6.7% from black carbon and 5% from anthropogenic trace elements to the daily exposure to PM2.5. The levels of mineral and marine elements increased with increasing particle size, while anthropogenic elements were present in higher concentrations in the finest particles. Particle size has been shown to influence the variability of daily dose deposited between the extrathoracic and alveolar-interstitial zones. On average, 3% of the PM deposited in the bronchial region, whereas 5% to 8% were found in the bronchiolar region. The level of physical activity had a significant contribution to the total daily dose.

Particulate matter-bound organic compounds: levels, mutagenicity, and health risks

Increased industrialization and consumption of fossil fuels in the Metropolitan Region of São Paulo (MRSP), Brazil, have caused a growth of the particulate matter emissions to the atmosphere and an increase in population health problems. Particulate and gaseous phase samples were collected in different short campaigns (2015, 2016, and 2017) near an urban-industrial area. Organic carbon (OC), elemental carbon (EC), polycyclic aromatic hydrocarbons (PAH), and its derivatives (nitro and oxy-PAH), n-alkanes, hopanes, and pesticides were determined. The Salmonella/microsome test confirmed the mutagenic activity of these samples. Among PAH, benzo(a)pyrene was detected as one of the most abundant compounds. Benzo(a)pyrene equivalent concentrations for PAH and nitro-PAH, and the associated risk of lung cancer, showed values above those recommended in the literature. The profile of n-alkanes confirmed the predominance of anthropogenic sources. Pesticide concentrations and estimated risks, such as the daily inhalation exposure and hazard quotient, suggest that exposure to these compounds in this area may be dangerous to human health.

AB0375 EXTERNAL VALIDATION OF THE GIANT CELL ARTERITIS PROBABILITY SCORE IN THE NETHERLANDS

Background:

Severe complications of giant cell arteritis (GCA), such as blindness and ischemic stroke, can be prevented by timely treatment. This requires early and accurate diagnosis. In 2019, Laskou et al. developed a clinical GCA probability score (GCAPS) that allows physicians to assess the probability of GCA at initial assessment. The GCAPS is suitable for easy implementation in daily practice. It has a high sensitivity (95.7%) and specificity (86.7%) at a cut-off value of 9.5 as proposed by Laskou et al.

Objectives:

The aim of this study was to externally validate the GCAPS in a general hospital.

Methods:

A retrospective cohort of patients with suspected GCA between January 1st 2017 and October 1st 2019 at Ziekenhuisgroep Twente (the Netherlands) was used. As the parameter extra-cranial artery abnormality was not available in our cohort, a modified version of the GCAPS was used (m-GCAPS). The m-GCAPS was compared to clinical diagnosis of a rheumatologist after six months in accordance with Laskou et al. The validity of the m-GCAPS was assessed by plotting a receiver operating characteristic (ROC) curve and assessing sensitivity and specificity for multiple cut-off values. For practical purposes, risk stratifications as proposed by Sebastian et al. (2020) were applied to our data (low-risk <9; intermediate-risk 9-12; high-risk >12).

Results:

In our cohort, 40 GCA patients and 95 controls (suspected of GCA) had complete records and were therefore used for analysis. In the patient group, 29 (72.5%) were female and mean (SD) age was 73.3 (1.6). The area under the ROC curve (AUC) was 0.83 (95% CI 0.75 – 0.91). At our optimal cut-off value of 10.5, sensitivity was 80.0% and specificity was 75.8%. In total, 5 patients and 45 controls were stratified as low, 7 patients and 35 controls as intermediate and 28 patients and 15 controls as high-risk.

Conclusion:

The m-GCAPS showed good discrimination in our cohort. Risk stratification of patients looks promising, although cut-off values by Sebastian et al. might need optimization based on population and modification to the GCAPS. Colour Doppler ultrasound is recommended by EULAR as the first-choice diagnostic test to confirm GCA in case of high pre-test probability and exclude GCA for low pre-test probability. The (m-)GCAPS may aid in quantification of this pre-test probability.

References:

[1]Laskou F, Coath F, Mackie SL et al. A probability score to aid the diagnosis of suspected giant cell arteritis. Clin Exp Rheumatol. 2019;37 Suppl 1(2):104–8.

[2]Sebastian A, Tomelleri A, Kayani A et al. Probability-based algorithm using ultrasound and additional tests for suspected GCA in a fast-track clinic. RMD Open. 2020 Sep 1;6(3):e001297.

[3]Dejaco C, Ramiro S, Duftner C et al. EULAR recommendations for the use of imaging in large vessel vasculitis in clinical practice. Ann Rheum Dis. 2018 May 1;77(5):636 LP – 643.

Table 1.

Cut-off values of the m-GCAPS stratified into risk categories as proposed by Sebastian et al. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) and the number of patients scoring above or below the cut-off values are described (optimal cut-off value in blue). The total number of patients with a score within low- (red), intermediate- (orange) and high- (green) risk categories are depicted.

GCA+ (N)N=40GCA- (N)N=95Scorem-GCAPSGCA+ (N)GCA- (N)Sens. (%)Spec. (%)PPV (%)NPV (%)Low-risk <95 (12.5%)45 (47.4%)5.5<5.501410014.733.1100>5.540818.5<8.554587.547.441.290>8.53550Intermediate-risk9-127 (17.5%)35 (36.8%)9.5<9.58568058.945.187.5>9.5323910.5<10.58728075.858.290>10.5322311.5<11.510747577.958.888.1>11.53021High-risk>928 (70.0%)15 (15.8%)12.5<12.512807084.265.187>12.5281514.5<14.518895593.778.683.2>14.522619.5<19.537957.510010072>19.530Figure 1.

ROC curve depicting sensitivity and (1-) specificity. The AUC was 0.83 (95.0% CI 0.75-0.91) with an optimal cut-off value of 10.5 (sensitivity 80.0%, specificity 75.8%).

Disclosure of Interests:

None declared

POS0261 DIAGNOSTIC PERFORMANCE AND CLINICAL UTILITY OF TWO REFERRAL RULES FOR INFLAMMATORY ARTHRITIS

Background:

The Rotterdam Early Arthritis Cohort (REACH) rule [1] and Clinical Arthritis RulE (CARE) [2] are both evidence-based and easy-to-use methods developed to identify the presence of inflammatory arthritis (IA) in patients suspected by their general practitioner (GP). However, the clinical utility of both models in daily clinical practice in an independent primary care setting has not yet been established. While developed for recognizing IA, we believe that it is also important that the broader spectrum of inflammatory rheumatic diseases (IRDs) is correctly classified from primary care, to facilitate appropriate referral towards outpatient rheumatology clinics.

Objectives:

The primary objective was to determine the diagnostic performance and clinical utility of the REACH and CARE referral rules in identifying IA in an independent population of unselected suspected patients from primary care. Secondly we will assess the diagnostic performance and clinical utility of both models in identifying IRDs.

Methods:

This prospective observational diagnostic study consisted of adults newly suspected by their GP for the need of referral to the rheumatology outpatient clinic of the Maasstad Hospital in Rotterdam. Primary outcome was IA, consisting of rheumatoid arthritis, axial spondylitis and psoriatic arthritis. Secondary outcome was IRD, defined as IA plus arthritis in systemic disorders such as systemic lupus erythematosus, systemic sclerosis and morbus sjögren. Rheumatologist diagnosis was used as gold standard. To evaluate the clinical performance of the REACH and CARE referral rules in this population, diagnostic accuracy measures were investigated using the Youden index (J) [3]. Moreover, a net benefit approach [4] was used to determine clinical utility of both rules when compared to usual care.

Results:

This study consisted of 250 patients (22.8% male) with a mean age of 50.8 years (SD 13.9 years). In total 42 (17%) patients were diagnosed with IA and 55 (22%) with an IRD. Figure 1 presents the diagnostic performance in IA (Figure 1A) and in IRD (Figure 1B). For the primary outcome, the REACH model shows an AUC of 0.72 (95% CI 0.64-0.80) and the optimal cut-off point is indicated (J). The CARE model shows an AUC of 0.82 (95% CI 0.75-0.88) and at J there is a somewhat higher sensitivity and specificity. When taking the broader spectrum of IRDs as outcome, the AUC was 0.66 (95% CI 0.58-0.74) for the REACH and 0.76 (95% CI 0.69-0.83) for the CARE model. The net benefit analysis with either IA or IRD as outcome showed that the CARE was of the highest clinical value when compared to usual care.

Conclusion:

Both the REACH and CARE model showed a good diagnostic performance for detecting IA in an independent population of unselected suspected patients from primary care. Although not specifically developed to recognize the entire spectrum of IRDs, the CARE shows a good performance in doing so. When evaluating clinical utility, we see that both rules have a net benefit in recognizing IA as well as IRDs compared to usual care, however the CARE shows superiority over the REACH. By using the CARE, over half of all suspected patients can be withheld from expensive outpatient rheumatology care, implied by the high specificity of 70%. These results support the idea that incorporating these easy-to-use methods into primary care could lead to providing patients the right care at the right place and improving value based health care.

References:

[1]ten Brinck RM, van Dijk BT, van Steenbergen HW, le Cessie S, Numans ME. Development and validation of a clinical rule for recognition of early inflammatory arthritis. BMJ Open; 2018: 8

[2]Alves, C. Improving early referral of inflammatory arthritis. In Early detection of patients at risk for rheumatoid arthritis – a challenge for primary and secondary care; 2015: 27-38 Ridderkerk, the Netherlands.

[3]Fluss R, Faraggi D, Reiser B. Estimation of the Youden Index and its associated cutoff point. Biom J; 2005: 47(4): 458-472

[4]Vickers AJ, Elkin EB. Decision curve analysis: a novel method for evaluating prediction models. Med Decis Making; 2006: 26(6): 565-574

Disclosure of Interests:

None declared

AB0367 DIAGNOSTIC DELAY IN PATIENTS WITH GIANT CELL ARTERITIS

Background:

Giant cell arteritis (GCA) is the most common systemic vasculitis in the elderly which can lead to severe complications when treatment is delayed. Therefore, timely diagnosis and start of treatment is essential. Several forms of delay (consultation, referral and diagnostic delay) can contribute to the total delay towards GCA diagnosis. In the Dutch healthcare system, treatment is not started by a general practitioner (GP). When GCA is suspected, GPs refer to specialists. In our hospital, a fast track clinic (FTC) is used to expedite diagnosis. However, information on factors contributing to delay is scarce.

Objectives:

The aim of this study was to describe the different components of delay towards diagnosis in GCA suspected patients in a general hospital, Ziekenhuisgroep Twente (the Netherlands).

Methods:

For this descriptive study, a retrospective cohort consisting of patients with suspected GCA between January 1st 2017 and October 1st 2019 was used to analyse components of delay in diagnosis, as suggested by Prior et al. Consultation delay was defined as the time between start of symptoms and a patient’s first consultation with a GP. Referral delay was defined as the time between a patient’s first consultation with a GP and first visit to the FTC. Diagnostic delay was defined as the time between the first visit to the FTC and treatment initiation. Total delay was defined as the time from symptom onset until start of treatment. Delays were described using the median and interquartile ranges (IQR).

Results:

In our cohort, 206 patients were included for analysis of whom 62 had GCA. Controls (n=144) were suspected of but did not have GCA. Comparing GCA patients with controls, 66.1% and 50.7% were female and the mean (SD) age was 74.2 (9.4) and 70.2 (11.0) years, respectively. In our cohort, the majority of patients (n=42, 67.7%) had cranial GCA (C-GCA). Furthermore, 8 (12.9%) had large vessel GCA (LV-GCA) and 12 (19.4%) had a combination of C-GCA and LV-GCA. For GCA patients, median consultation delay was 2.1 (IQR 0.8-5.8) weeks, referral delay 1.4 (IQR 0.4-4.6) weeks and diagnostic delay 0 (IQR 0-0.1) weeks (Figure 1). For delay regarding consultation and referral, results of controls were comparable to GCA patients. The median total delay was 4.4 weeks (IQR 1.57-10.14) for GCA patients.

Conclusion:

With a median total delay of 4.4 weeks, delay in our cohort is almost half the delay described in a review by Prior et al. This difference might be due to FTC implementation and subsequent awareness in our hospital and by local GPs. Patients generally received treatment within one day after FTC visit. Nevertheless, contribution of consultation and referral delay is not resolved by introduction of the FTC, as shown in our data. Timely diagnosis is essential as severe complications can develop instantly, which emphasizes the need to tackle consultation and referral delay.

References:

[1]Prior JA, Ranjbar H, Belcher J, et al. Diagnostic delay for giant cell arteritis – a systematic review and meta-analysis. BMC Med. 2017;15(1):120.

Table 1.

Baseline characteristics of GCA patients and controls in our retrospective cohort. *CDUS=Colour Doppler Ultrasound; **Temporal Artery Biopsy;***18-FDG-Positron Emission Tomography/Computed Tomography.

GCA patients (n=62)Controls (n=144)RangeRangeGender, % female (n)66.1 (41)50.7 (73)Age (years), mean (SD)74.2 (9.4)51 – 9170.2 (11.0)50 – 97ESR, mean (SD)Missing78.4 (30.3)322 – 12039.9 (32.4)92 – 124CRP, mean (SD)74.7 (60.0)2 - 28335.8 (52.9)0.4 -280Missing16Polymyalgia Rheumatica,% yes (n)21 (13)11.8 (17)Cranial symptoms,% yes (n)80.6 (50)75.0 (108)Vision loss, %yes (n)Compliant with GCA (i.e. AION, central retinal artery occlusion diplopia)27.4 (17)15.3 (22)Diagnostics CDUS* %yes (n)96.8 (60)96.5 (139) TAB** %yes (n)58.1 (36)18.8 (27) PET/CT***%yes (n)40.3 (25)16.0 (23)Figure 1.

Description of consultation (A); referral (B); diagnostic (C) and total (D) delay in weeks for controls (black) and GCA patients (green), stratified for C-GCA (red), LV-GCA (blue) and C/LV-GCA (purple). 1Not possible for controls as no GCA-indicated treatment was started.

Disclosure of Interests:

None declared

Towards a model for aerosol removal by rain scavenging: The role of physical-chemical characteristics of raindrops

A one-year study was carried out in León, Spain, in order to characterize physically and chemically the precipitation. With the aim of studying the scavenging process of atmospheric pollutants, scavenging ratio and removal coefficients were calculated through physical parameters of raindrops (obtained by disdrometer data) and through chemical properties of aerosols. Finally, linear models for the prediction of the chemical composition of rainwater and the efficiency of the removal effect were established. In general, the rainwater was dominated by NH₄⁺ > SO₄^2- > NO₃^- in all seasons. Higher ion concentrations and conductivity and lowest pH were observed in summer, due to the low volume of rain. In winter, the high values of Na⁺ and Cl^- in the rainwater showed the contribution from marine sources, while in summer the high concentrations of Ca²⁺, Mg²⁺, SO₄^2-, NH₄⁺ and NO₃^- reflected the contribution from both crustal and anthropogenic sources. The linear models revealed that the amount of dissolved organic carbon and of the water-soluble ions in rain samples, Ca²⁺, SO₄^2-, NO₃^-, increases with the volume swept by the falling drops. Insoluble carbon fraction has a negative dependence with the volume swept and positive with the diameter of the raindrop. Removal coefficients are affected by the concentration in the air of each species before precipitation, the duration of the event and the time elapsed between two precipitation events.

Characterization of aerosol sources in León (Spain) using Positive Matrix Factorization and weather types

A one-year aerosol sampling campaign, between 2016 and 2017, was conducted in a suburban area of León city, Spain. An association between the Positive Matrix Factorization (PMF) results and air masses through circulation weather types was carried out, through the construction of linear models from the PM₁₀ concentrations and its chemical composition. The aerosol sources, identified by PMF six-factor solution, were: traffic (29%), aged sea salt (26%), secondary aerosols (16%), dust (13%), marine aerosol (7%) and biomass burning (3%). Traffic and secondary factors showed the highest PM₁₀ contribution in the hybrid cyclonic types with wind component from the first and second quadrant. Anticyclonic types with wind component from the first quadrant exhibited high values of secondary, aged sea salt and dust factors. The highest contributions of the dust factor were also associated with northerly types. The linear models built for estimating the source apportionment of PM₁₀, from aerosol chemical composition and geostrophic flow, showed positive coefficients for: westerly flows (WF) in marine factor, southerly flows (SF) in secondary and traffic factors, and shear southerly vorticities (ZS) in dust factor. Negative dependences were observed for ZS in aged sea salt factor and for SF in dust factor. The PM₁₀ mass concentration calculated by the linear models and by the PMF model were strongly correlated. This can be very useful to determine the contribution of a specific source to PM₁₀ in León, only by knowing some meteorological and chemical variables.

Settleable Dust and Bioburden in Portuguese Dwellings

Monitoring campaigns in several buildings have shown that occupants exposed to contaminated indoor air generally exhibit diverse health symptoms. This study intends to assess settleable dust loading rates and bioburden in Portuguese dwellings by passive sampling onto quartz fiber filters and electrostatic dust cloths (EDCs), respectively. Settled dust collected by EDCs was analyzed by culture-based methods (including azole-resistance screening) and qPCR, targeting four different toxigenic Aspergillus sections (Flavi, Fumigati, Circumdati, and Nidulantes). Dust loading rates and bioburden showed higher variability in the summer season. In both seasons, Penicillium sp. was the one with the highest prevalence (59.1% winter; 58.1% summer), followed by Aspergillus sp. in winter (13.0%). Fungal contamination increased in the winter period, while bacterial counts decreased. Aspergillus sections Circumdati and Nidulantes, detected in voriconazole supplemented media, and Aspergillus sections Fumigati and Nidulantes, detected by molecular tools, were found in the winter samples. This study reinforces the importance of applying: (a) Passive sampling methods in campaigns in dwellings; (b) two different culture media (MEA and DG18) to assess fungi; (c) in parallel, molecular tools targeting the most suitable indicators of fungal contamination; and (d) azole resistance screening to unveil azole resistance detection in fungal species.

Cross-cultural validation of the Portuguese from Portugal version of the test for respiratory and asthma control in kids questionnaire

Summary

Objective. The Test for Respiratory and Asthma Control in Kids (TRACK) is a tool to assess asthma control in preschool children. This study aims to validate the Portuguese from Portugal version of the TRACK questionnaire. Methods. A prospective cohort study was carried out to assess their psychometric characteristics. Caregivers of 141 children under age 5 with asthma symptoms were enrolled. Results. Internal reliability was close to 0.70 (Cronbach's α). The test-retest reliability was 0.87. TRACK scores were different between well, partially, and non-controlled asthma groups (p less than 0.001). Patients rated as having better control showed an increase in TRACK scores. Conclusions. The Portuguese version of the TRACK questionnaire is accurate and reliable for monitoring asthma control. Its use may help to overcome challenges with the management of this age group.

Sustainable plant polyesters as substrates for optical gas sensors

The fast and non-invasive detection of odors and volatile organic compounds (VOCs) by gas sensors and electronic noses is a growing field of interest, mostly due to a large scope of potential applications. Additional drivers for the expansion of the field include the development of alternative and sustainable sensing materials. The discovery that isolated cross-linked polymeric structures of suberin spontaneously self-assemble as a film inspired us to develop new sensing composite materials consisting of suberin and a liquid crystal (LC). Due to their stimuli-responsive and optically active nature, liquid crystals are interesting probes in gas sensing. Herein, we report the isolation and the chemical characterization of two suberin types (from cork and from potato peels) resorting to analyses of gas chromatography–mass spectrometry (GC-MS), solution nuclear magnetic resonance (NMR), and X-ray photoelectron spectroscopy (XPS). The collected data highlighted their compositional and structural differences. Cork suberin showed a higher proportion of longer aliphatic constituents and is more esterified than potato suberin. Accordingly, when casted it formed films with larger surface irregularities and a higher C/O ratio. When either type of suberin was combined with the liquid crystal 5CB, the ensuing hybrid materials showed distinctive morphological and sensing properties towards a set of 12 VOCs (comprising heptane, hexane, chloroform, toluene, dichlormethane, diethylether, ethyl acetate, acetonitrile, acetone, ethanol, methanol, and acetic acid). The optical responses generated by the materials are reversible and reproducible, showing stability for 3 weeks. The individual VOC-sensing responses of the two hybrid materials are discussed taking as basis the chemistry of each suberin type. A support vector machines (SVM) algorithm based on the features of the optical responses was implemented to assess the VOC identification ability of the materials, revealing that the two distinct suberin-based sensors complement each other, since they selectively identify distinct VOCs or VOC groups. It is expected that such new environmentally-friendly gas sensing materials derived from natural diversity can be combined in arrays to enlarge selectivity and sensing capacity.

Chemical composition of rainwater under two events of aerosol transport: A Saharan dust outbreak and wildfires

A one-year campaign of joint sampling of aerosols and precipitation, carried out in León, Spain, allowed to study the impact of two special events that affected the air quality in the north of the country, on rainfall in the city: a period with wildfires and a Saharan dust intrusion. The wildfires that occurred in northern Portugal and northwestern Spain in August 2016 affected the chemistry of rainfall on 15 August 2016, causing an increase in concentrations of NH₄⁺, Na⁺, Cl^-, K⁺, Mg²⁺, Ca²⁺, SO₄^2- and NO₃^- and in the concentrations of organic acids, which was reflected in the levels of soluble and insoluble organic carbon. This led to acidification of rainwater (pH = 4.8). The second precipitation event was registered between 11 and 14 February 2017, during which the rainwater was collected in four daily fractions (P₁, P₂, P₃ and P₄). The rain sample of 12 February (P₂) coincided with a Saharan dust intrusion that reached northern Iberia that day. The chemical composition of P₂ showed an increase in the Ca²⁺ (>800%), Mg²⁺ (71%), Cl^- (62%), and SO₄^2- (33%) concentrations, with respect to P₁. The input of crustal elements to the atmosphere helped to neutralize the P₂ rainwater, causing pH values higher than 6.5. Once the dust intrusion left the north of the Peninsula, the composition of rainwater P₃ and P₄ revealed a mixture of marine contribution with local anthropogenic emissions, as well as a decrease in ion concentrations and conductivity, and an increase in pH values.

Compliance of indoor air quality during sleep with legislation and guidelines - A case study of Lisbon dwellings

This study aimed to provide a comprehensive characterisation of the indoor air quality during the sleeping period of 10 couples at Lisbon dwellings, using a multi-pollutant approach, and to understand how the compliance with legislation and guidelines was to assure a good indoor air quality. The assessment of indoor air quality was conducted in the cold season using real time monitors during the sleeping period for comfort parameters (temperature and relative humidity) and air pollutants (carbon dioxide - CO₂, carbon monoxide - CO, formaldehyde - CH₂O, total volatile organic compounds - VOCs, and particulate matter - PM_2.5 and PM₁₀), together with active sampling of bioaerosols (fungi and bacteria) before and after the sleeping period. Lower compliance (less than 50% of the cases) with the Portuguese legislation was found for temperature, CO₂ (3440 ± 1610 mg m^-3), VOCs (1.79 ± 0.99 mg m^-3) and both bioaerosol types. In 70% of the cases, PM_2.5 (15.3 ± 9.1 μg m^-3) exceeded the WHO guideline of 10 μg m^-3. All bedrooms presented air change rates above the recommended minimum value of 0.7 h^-1, highlighting that a good indoor air quality during sleep is not guaranteed.

Epidemiology of Carbapenemase-Producing Klebsiella pneumoniae in a Portuguese Tertiary Hospital

Background

Carbapenemase-producing Klebsiella pneumoniae (CPKp) are considered a public health problem. To manage this multidrug-resistant organism (MDRO), it is important to identify individuals at higher risk. We describe risk factors for CPKp among a population who acquired this MDRO, in a tertiary hospital Center (THC), from 2017 to 2019.

Methods

Descriptive study, with data from medical record, in a 1100 bed THC, with active surveillance (high risk population at admission and CPKp direct contacts). Participants: patients &gt; =18 years old, with length of stay (LOS) &gt;48 hours, in which CPKp was identified in clinical samples &gt; =48 h after admission and without previous history of this MDRO.

Results

Incidence rate increased from 0.031 (2017) to 0.090 (2018) cases per 1000 patient-days and was 0.081 in 2019 (p = 0.004). Evolution of CPKp proportion was 1.6%, 3.9% and 4.1%, respectively. In 2019, 12 patients (40.0%) were at intensive care when this MDRO was detected. During these 3 years, CPKp was more frequently identified in urine (31.3 - 54.5%) and respiratory products (13.3 - 36.4%). The median LOS until CPKp isolation was 10.0 to 24.0 days and, until discharge, 15.0 to 25.5 days. Fatal outcome occurred in 8 (25.0%) and 7 (23.3%) patients in 2018 and 2019, respectively. Most cases were exposed to antibiotics (81.8 - 90.6%), had a urinary catheter (63.6 - 75.0%) and were dependent for hygiene activities (63.6 - 66.7%). Many had a central line (21.9 - 43.3%), previous surgery (45.5 - 63.3%) and hospital admission in the previous 6 months (27.3 - 40.6%). Along these 3 years, none of these variations was statistically significant.

Conclusions

In this THC, CPKp increased from 2017 to 2018 and remained stable afterwards. It affected mostly male patients, exposed to antibiotics, with urinary catheter and dependent in their hygiene activities. In order to have an adequate CPKp containment strategy it is essential to know the population who acquired this MDRO.

Key messages

CPKp increased from 2017 to 2018 and remained stable afterwards, affecting mostly male patients, exposed to antibiotics, with urinary catheter and dependent in their hygiene activities. In order to have an adequate CPKp containment strategy it is essential to know the population who acquired this MDRO during their stay.

Fine Particulate Matter and Gaseous Compounds in Kitchens and Outdoor Air of Different Dwellings

Passive diffusion tubes for volatile organic compounds (VOCs) and carbonyls and low volume particulate matter (PM_2.5) samplers were used simultaneously in kitchens and outdoor air of four dwellings. PM_2.5 filters were analysed for their carbonaceous content (organic and elemental carbon, OC and EC) by a thermo-optical technique and for polycyclic aromatic hydrocarbon (PAHs) and plasticisers by GC-MS. The morphology and chemical composition of selected PM_2.5 samples were characterised by SEM-EDS. The mean indoor PM_2.5 concentrations ranged from 14 µg m⁻³ to 30 µg m⁻³, while the outdoor levels varied from 18 µg m⁻³ to 30 µg m⁻³. Total carbon represented up to 40% of the PM_2.5 mass. In general, the indoor OC/EC ratios were higher than the outdoor values. Indoor-to-outdoor ratios higher than 1 were observed for VOCs, carbonyls and plasticisers. PAH levels were much higher in the outdoor air. The particulate material was mainly composed of soot aggregates, fly ashes and mineral particles. The hazard quotients associated with VOC inhalation suggested a low probability of non-cancer effects, while the cancer risk was found to be low, but not negligible. Residential exposure to PAHs was dominated by benzo[a]pyrene and has shown to pose an insignificant cancer risk.

Factors associated with asthma control in 121 preschool children

BACKGROUND AND OBJECTIVE

There are controversial data about risk factors for uncontrolled asthma in preschool children. Objective: This study aims to explore the association between clinical and functional parameters and the lack of asthma control in preschool children.

METHODS

Children 3-5 years-old with asthma and healthy controls were recruited. A questionnaire was used to identify the potential risk factors of uncontrolled asthma as defined by GINA (Global INitiative for Asthma) criteria. Lung function and bronchial reversibility were evaluated through impulse oscillometry (IOS) and spirometry. Adjusted odds ratios (OR) were estimated based on multivariable generalized additive regression models. The discriminative ability of the models was measured by the area under the receiver operating characteristic curve (AUC).

RESULTS

121 children were included, 107 of which had asthma and 14 were healthy controls. Fifty-three patients (50%) had uncontrolled asthma. After adjustment, the variables associated with an increased risk of lack of control were: "More than 3 flare-ups in last 12 months", "moderate to severe rhinitis", "relative variation in post-bronchodilator FVC and FEV1". The AUC of the final models that included variation of FVC or FEV1 were 0.82 and 0.81, respectively. R5-20, R5-20% and AX z-score values of the healthy group were lower than those of children with asthma.

CONCLUSION

In preschool children, clinical and functional parameters are associated with uncontrolled asthma. More studies are needed to confirm usefulness of the IOS.

Impact of wood combustion on indoor air quality

The incomplete wood combustion in appliances operated in batch mode is a recognised source of both in- and outdoor airborne pollutants, especially particulate matter (PM). Data on pollutant levels and PM characteristics in households with wood burning devices in developed countries are scarce with most studies describing stove change out programmes or other intervention measures. The aim of the present study was to simultaneously evaluate indoor and outdoor concentrations of CO, CO₂ and PM₁₀ during the operation of wood burning appliances (open fireplace and woodstove) in unoccupied rural households. PM₁₀ samples were analysed for water soluble inorganic ions, major and trace elements, organic carbon (OC), elemental carbon (EC), and detailed organic speciation. The CO 8-hour average concentrations did not exceed the protection limit despite the sharp increases observed in relation to background levels. During the open fireplace operation, PM₁₀ levels rose up 12 times compared to background concentrations, while the airtight stove resulted in a 2-fold increase. The inhalation cancer risk of particulate bound PAHs in the room equipped with woodstove was estimated to be negligible while the long-term exposure to PAH levels measured in the fireplace room may contribute to the development of cancer. The excess lifetime cancer risk resulting from the particle-bound Cr(VI) exposure during the fireplace and woodstove operation was higher than 1.0 × 10^-6 and 1.0 × 10^-5, respectively. Levoglucosan was one of the most abundant individual species both indoors and outdoors. This study underlines air pollution hazards and risks arising from the operation of traditional wood burning appliances.

Aethalometer measurements in a road tunnel: A step forward in the characterization of black carbon emissions from traffic

A sampling campaign was conducted in the Liberdade Avenue tunnel (Braga, Portugal) during a week (with 56,000 vehicles) to monitor black carbon (eBC-equivalent black carbon) by means of an Aethalometer AE-31, and gaseous pollutants (CO₂, CO, NO_x). Inside the tunnel, the mean eBC mass concentration was 21 ± 10 μg m^-3, reaching a maximum hourly value of 49.0 μg m^-3. An hourly and weekday-weekend study was carried out. Regarding the Absorption Ångström exponent (AAE), a mean value of 0.97 ± 0.10 was obtained, for a source of practically pure traffic. There was a positive significant correlation between eBC and the number of light vehicles (r = 0.47; p < 0.001) and between eBC and the gaseous emissions: CO (r = 0.67; p < 0.001), CO₂ (r = 0.71; p < 0.001), NO (r = 0.63; p < 0.001) and NO₂ (r = 0.70; p < 0.001). The mean black carbon emission factors (EF_BC) inside the tunnel were 0.31 ± 0.08 g (kg fuel)^-1 and 0.11 ± 0.08 mg veh^-1 km^-1, similar to those found in other studies for gasoline and diesel vehicles in road tunnels.

Air quality of an urban school in São Paulo city

A major campaign was carried out in indoor and outdoor environments in a school located in the university campus of the city of São Paulo. Elements, PAH, oxy-PAH, water-soluble ions and black carbon were determined and compared with preliminary campaigns. The results indicated that the concentrations of particles and organic compounds were higher indoors. Some high molecular weight compounds, attributed to vehicular emissions, were more abundant outdoors. The associated health risk was found to be low. 2-Methylanthraquinone and benzo(a)anthracene-7,12-dione were detected in the indoor samples, denoting the infiltration of vehicle exhaust. The observation of black carbon also corroborates the contribution of traffic emissions. For most of the elements, except for chromium, iron and manganese, the concentrations obtained in indoors were higher than outdoors, mainly due to soil resuspension. Chromium and manganese likely derived from emissions of the vehicle powered by mixtures of ethanol and gasoline. Water-soluble inorganic ions species denoted the influence of soil resuspension and human activities.

Plantar flexion, dorsiflexion, range of movement and hindfoot deviation are important determinants of foot function in children

PURPOSE

Paediatric foot surgery is often performed to restore anatomical shape or range of movement (ROM). The purpose of this study was to determine how foot morphology and ROM are associated with foot function in children aged five to 16 years of age.

METHODS

Participants included 89 patients with foot disorders and 58 healthy controls. In addition to measuring children's foot alignment and ankle ROM, children and parents completed the Oxford Ankle and Foot Questionnaire (OxAFQ).

RESULTS

Mean age was 10.3 years for patients and 10.6 years for controls; 53 of 89 patients had clubfoot. All foot measurements and scores on the OxAFQ significantly differed (p < 0.001) between patients and controls. Patients and their parents significantly differed on the physical (p = 0.03) and emotional (p = 0.02) domains of the OxAFQ, with parents' ratings being lower than their children. Moderate correlations (r = 0.54 to 0.059; p < 0.001) were found between physical domain (reported by parents on the OxAFQ) and dorsiflexion-knee flexed, and foot- arc-of-movement. Moderate correlations were found between physical domain (reported by children on OxAFQ) and foot-arc-of-movement (r = 0.56; p < 0.001). Patients in the surgical group showed moderate correlations (r = 0.57;, p < 0.001) between physical domain (reported by children on OxAFQ) and plantar flexion, and foot arc-of-movement. The control group and the patients in non-surgical subgroup showed no significant correlations.

CONCLUSION

Plantar flexion, arc of ankle ROM and hindfoot alignment impact foot function in children with foot deformities. Parents report significantly lower scores on the OxAFQ when judging foot functioning.

LEVEL OF EVIDENCE

Level II. Prognostic Studies.

Unusual winter Saharan dust intrusions at Northwest Spain: Air quality, radiative and health impacts

Saharan air masses can transport high amounts of mineral dust particles and biological material to the Iberian Peninsula. During winter, this kind of events is not very frequent and usually does not reach the northwest of the Peninsula. However, between 21 and 22 February 2016 and between 22 and 23 February 2017, two exceptional events were registered in León (Spain), which severely affected air quality. An integrative approach including: i) typical synoptic conditions; ii) aerosol chemical composition; iii) particle size distributions; iv) pollen concentration; v) aerosol optical depth (AOD); vi) radiative forcing and vii) estimation of the impact of aerosols in the respiratory tract, was carried out. In the global characterization of these events, the exceedance of the PM₁₀ daily limit value, an increase in the coarse mode and a rise in the iron concentration were observed. On the 2016 event, an AOD and extinction-related Ångström exponent clearly characteristic of desert aerosol (1.1 and 0.05, respectively) were registered. Furthermore, pollen grains not typical of flowering plants in this period were identified. The chemical analysis of the aerosol from the 2017 event allowed us to confirm the presence of the main elements associated with mineral sources (aluminum, calcium, and silica concentrations). An increase in the SO₄^2-, NO₃^- and Cl^- concentrations during the Saharan dust intrusion was also noted. However, in this event, there was no presence of atypical pollen types. The estimated dust radiative forcing traduced a cooling effect for surface and atmosphere during both events, corroborated by trends of radiative flux measurements. The estimated impact on the respiratory tract regions of the high levels of particulate matter during both Saharan dust intrusions showed high levels for the respirable fraction.

Bracing in clubfoot: do we know enough?

PURPOSE

The Ponseti method is widely used in clubfoot treatment. Long-term follow-up shows high patient satisfaction and excellent functional outcomes. Clubfoot tendency to relapse is a problem yet to solve. Given the importance of bracing in relapse prevention, we ought to discuss current knowledge and controversies about bracing.

METHODS

We describe types of braces used, with its advantages and disadvantages, suggesting bracing schedules and duration. We identify bracing problems and pinpoint strategies to promote adherence to bracing.

RESULTS

When treating a clubfoot by the Ponseti method, the corrected foot should be held in an abducted and dorsiflexed position, in a foot abduction brace (FAB), with two shoes connected by a bar. The brace is applied after the clubfoot has been completely corrected by manipulation, serial casting and possibly Achilles tenotomy. Bracing is recommended until four to five years of age and needs to be fitted to the individual patient, based on age, associated relapse rate and timing when correction was finished. Parental non-adherence to FAB use can affect 34% to 61% of children and results in five- to 17-fold higher odds of relapse. In patients who have recurrent adherence problems, a unilateral lower leg custom-made orthosis can be considered as a salvage option. Healthcare providers must communicate with patients regarding brace wearing, set proper expectations and ensure accurate use.

CONCLUSION

Bracing is essential for preventing clubfoot relapse. Daily duration and length of bracing required to prevent recurrence is still unknown. Prospective randomized clinical trials may bring important data that will influence clinicians' and families' choices regarding bracing.

LEVEL OF EVIDENCE

V.

Comparison of indoor air quality during sleep in smokers and non-smokers' bedrooms: A preliminary study

People spend one third of their life sleeping, but the bedroom, as a specific micro-environment, is often neglected when assessing human exposure to air pollutants. However, exposure during sleep may be significant in the long-term to the integrated individual exposure. This study aimed to assess the exposure during sleep, focusing on a multi-pollutant approach (comfort parameters, carbon dioxide - CO₂, carbon monoxide - CO, formaldehyde (CH₂O), total volatile organic compounds (VOCs), particulate matter - PM_2.5 and PM₁₀ - and ultrafine particles, particle number concentrations - PNC - and lung deposited surface area - LDSA). For that, the air quality during sleep (in real conditions) was monitored using real-time devices in 12 bedrooms of urban (Lisbon and Vila Franca de Xira) and rural (Ponte de Sor) areas of Portugal for one night. Volunteers were smokers and non-smokers. Considering the Portuguese legislation for indoor air quality (IAQ), 67% of the bedrooms registered CO₂ levels above the limit value, while CH₂O, VOC, PM₁₀ and PM_2.5 thresholds were exceeded in 30, 100, 36, and 45% of cases, respectively. Regarding ultrafine parameters, LDSA and PNC ranged from 7.3 to 95.2 μm²/cm³ and from 0.6 to 4.8 × 10³/cm³, respectively. Even with no smoking indoors, smokers' bedrooms were found to have significant higher levels of CO, CH₂O, PM_2.5, PM₁₀ and LDSA than non-smokers' bedrooms, showing the effect of thirdhand smoke, exhalation of pollutants after smoking and infiltration on the degradation of the air quality in the bedroom. A recent new model of real-time monitor was also used for a wide set of IAQ parameters. Its performance to measure PM_2.5 and CO₂ was assessed, showing its applicability in real conditions. Although often neglected, these micro-environments should be considered in the integrated individual exposure to air pollutants and further studied. MAIN FINDINGS OF THE WORK: Several pollutants (CO₂, PM, VOCs and CH₂O) exceeded the guidelines during sleep; smokers are exposed to higher levels of CO, CH₂O, PM, and LDSA than non-smokers while sleeping.