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Players involved in the various football codes compete throughout the calendar year around the world. Therefore, environmental stressors such as temperature and altitude should be considered in preparation for, and during, matches. We aimed to systematically review the observational and quasi-experimental studies that have been specifically designed to quantify the effects of temperature (hot or cold) high altitude on in-match physical performance indicators. A search of electronic databases (Web of Science, Scopus, SPORTDiscus, PubMed/MEDLINE) was conducted, resulting in 19,424 papers being identified as relevant. Following sifting in relation to the eligibility criteria, 12 papers were deemed directly relevant. The reviewed studies scored 6-9 (on a 0-9 scale) for quality assessment using a previously used scale. The major outcome variables relevant to the current review were total distance (m), high speed running (m) and high-speed runs (count) measured during matches. Standardized effect sizes (ES) were heterogeneous across studies for total distance (ES: -0.96 to -0.14) and high-speed running (ES: -0.69 to 0.12) for >1000 m vs sea-level, time spent at the given altitude being a putative factor for this heterogeneity. Heat had mainly detrimental effects on performance, but ES were, again, heterogeneous across studies (ES: -1.25 to 0.26), dependent on temperature. Given the small number of studies that only involved mostly male athletes, and large heterogeneity across studies, more research needs be conducted on physical performance in these environmental conditions, with attention paid to standardizing outcomes and broadening the approaches of studies to guide future decision making in professional sporting environments.

Invasive lobular carcinoma (ILC) is thought be a unique entity with higher rates of multifocal/multicentric and bilateral disease. This study aimed to evaluate the true extent of the disease, risk of bilaterality, lymph node involvement, and impact of preoperative imaging to help guide surgical decision making. A retrospective analysis identified patients treated for ILC between 2004 and 2017. Clinical staging and pathologic results were compared. Follow-up details including local recurrence, contralateral breast cancer (CBC), and survival outcomes were evaluated. The study identified 692 patients with ILC, including 43 patients (6%) with a diagnosis of CBC and 232 patients (33%) with a diagnosis of multifocal/multicentric disease at presentation. Preoperative magnetic resonance imaging (MRI) led to an identification of additional disease in 20% of the patients. Preoperative MRI resulted in a more accurate prediction of tumor size staging but did not improve the discordance between clinical and pathologic nodal staging. Overall, the rate of imaging occult lymph node disease was 24%. At the 6-year follow-up evaluation, a local recurrence had developed in 2.3%, a CBC in 2.3, and a distant metastasis in 9.4% of the patients. The overall survival rate was 96% at 3 years and 91% at 5 years. Invasive lobular carcinoma is a distinct subset of cancer that poses a diagnostic staging challenge. The results of this study favor MRI for accurate tumor staging and for improving detection of multicentricity and bilaterality. However, clinicians should be aware of the higher likelihood of occult lymph node involvement with ILC and subsequent early metastasis.

Inhalable particulate matter (PM) is a health concern, and people living in large cities such as Bangkok are exposed to high concentrations. This exposure has been linked to respiratory and cardiac diseases and cancers of the lung and brain. Throughout 2018, PM was measured in northern Bangkok near a toll road (13.87°N, 100.58°E) covering all three seasons (cool, hot and rainy). PM10 was measured in 24- and 72-h samples. On selected dates aerodynamic size and mass distribution were measured as 3-day samples from a fixed 5th floor inlet. Particle number concentration was measured from the 5th floor inlet and in roadside survey measurements. There was a large fraction of particle number concentration in the sub-micron range, which showed the greatest variability compared with larger fractions. Metals associated with combustion sources were most found on the smaller size fraction of particles, which may have implications for associated adverse health outcomes because of the likely location of aerosol deposition in the distal airways of the lung. PM10 samples varied between 30 and 100 μg m−3, with highest concentrations in the cool season. The largest metal fractions present in the PM10 measurements were calcium, iron and magnesium during the hot season with average airborne concentrations of 13.2, 3.6 and 2.0 μg m−3, respectively. Copper, zinc, arsenic, selenium, molybdenum, cadmium, antimony and lead had large non-crustal sources. Principal component analysis (PCA) identified likely sources of the metals as crustal minerals, tailpipe exhaust and non-combustion traffic. A health risk analysis showed a higher risk of both carcinogenic and non-carcinogenic health effects in the drier seasons than the wet season due to ingestion of nickel, arsenic, cadmium and lead. Graphical abstract

Carbon nanotube (CNT) in vivo inhalation studies are increasingly providing estimates of the quantity of material deposited in the lung, generally estimated using standard formulae and pulmonary deposition models. These models have typically been developed and validated using data from studies using sphere-like particles. Given the importance of particle morphology to pulmonary deposition, the appropriateness of such an approach was explored to identify any potential limitations. Aerosolized CNT particles typically form ‘fiber-like’ and/or ‘broadly spherical’ agglomerates. A review of currently used deposition models indicates that none have been directly validated against results for CNT, however, models for spherical particles have been extensively validated against a wide range of particle sizes and materials and are thus expected to provide reasonable estimates for most ‘broadly spherical’ CNT particles, although experimental confirmation of this would be of benefit, especially given their low density. The validation of fiber deposition models is significantly less extensive and, in general, focused on larger particles, e.g. asbestos. This raises concerns about the accuracy of deposition estimates for ‘fiber-like’ CNT particles and recommendations are made for future research to address this. An appreciation of the uncertainties on CNT deposition estimates is important for their interpretation and thus it is recommended that model sensitivity and uncertainty assessments be undertaken. Issues surrounding the measurement and derivation of model input data are also addressed, including instrument responses and particle density assessment options. Recommendations are also made for aerosol characterization to ‘future-proof’ CNT inhalation studies regarding advances in deposition modeling and toxicological understanding.

Background There is increasing interest in better understanding the biology and clinical presentation of invasive lobular cancer (ILC), which is the most common special histological subtype of breast cancer. Limited large contemporary data sets are available allowing comparison of clinicopathologic features between ILC and invasive ductal cancer (IDC). Methods The Great Lakes Breast Cancer Consortium was formed to compare clinical behavior of ILC (n = 3617) and IDC (n = 30 045) from 33 662 patients treated between 1990 and 2017 at 3 large clinical centers. We used Kaplan-Meier analysis, Cox proportional hazards modeling, and propensity score matching to evaluate treatment differences and outcomes. All statistical testing used 2-sided P values. Results Compared with IDC, patients with ILC were more frequently diagnosed at later stages and with more lymph node involvement (corrected P Conclusions This large, retrospective, collaborative analysis with 3 clinical centers identified meaningful differences in clinicopathological features between ILC and IDC, providing further evidence that these are 2 different entities requiring different clinical management.

Inhalable particulate matter (PM) is a health concern, and people living in large cities such as Bangkok are exposed to high concentrations. This exposure has been linked to respiratory and cardiac diseases and cancers of the lung and brain. Throughout 2018, PM was measured in northern Bangkok near a toll road (13.87°N, 100.58°E) covering all three seasons (cool, hot and rainy). PM

Field experiments were undertaken in the summer of 2015 in Manchester, UK, to investigate the dispersion behaviour and infiltration into buildings of gas-phase pollutants over horizontal distances of 1–5 km. Inert cyclic perfluorocarbon tracers were released for 15 min at either one or three release points and samples taken in locations indoors and outdoors up to 2 km downwind. Background measurements of these cyclic perfluorocarbons range between 5.6 and 12.6 parts per quadrillion (ppq). On most occasions, tracer concentrations are higher on the sixth floor than at ground level. Tracer concentrations persist in the least well-ventilated rooms after concentrations return to background levels outdoors. The highest tracer concentrations, 329 ppq above background, occur at dawn on 23 July from a sixth-floor sampling position during thermally stable conditions. At low wind speeds, tracer is detected upwind of the prevailing wind direction; on 24 July, tracer is detected to the north-west of the release point for north-north-east wind direction. A simple street network model does not predict tracer concentrations at low wind speeds over the km scales in this investigation due to tracer likely escaping the urban canopy. Predictions from a simple correlation model overestimate concentrations originating from distant sources, which is believed to be due to infiltration into buildings along the journey from source to receptor. A Gaussian plume model predicts the highest tracer concentrations for most receptor points on 23 July when the lowest Obukhov length of – 26 m was measured, agreeing with tracer measurements.

Background: Invasive lobular carcinoma (ILC) is the second most common invasive breast cancer histology. Within ILC histology, there are multiple subtypes. The most common subtype is “classic” characterized by small single files of cells invading the stroma. Another subtype of clinical interest is “pleomorphic” which is characterized by larger cells with varied nuclear appearance. Rare and not well understood, pleomorphic ILC is traditionally viewed as an aggressive form of ILC. Studies have shown a relatively consistent association between pleomorphic ILC and certain high risk features such as advanced stage, HER2 positivity, and lymph node involvement. Survival outcome data comparing pleomorphic ILC to non-pleomorphic ILC has yielded varied results. Methods: A retrospective study of a large institutional database was conducted to characterize patients with ILC treated from 2004-2017. Patient and disease characteristics were recorded, including disease staging, biomarker profile, specific ILC histology, treatment details, and recurrence events. Findings were analyzed and overall survival (OS) and recurrence free survival (RFS) were compared between pleomorphic and non-pleomorphic ILC cohorts. Propensity score matching was also completed to account for confounding variables. Results: A total of 691 patients who had surgery were studied (mean age 61.6 ± 11.6 years old, 86.9% Caucasian, 98.3% with endocrine therapy), including 100 (14.4%) with pleomorphic ILC and 591 (85.5%) with non-pleomorphic ILC. Compared to non-pleomorphic ILC, pleomorphic ILC was less likely to be estrogen receptor (ER) positive (94% vs. 98%, p=0.004), more likely to be HER2 positive (12% vs. 7%, p=0.07), more likely to be grade 3 (33% vs. 2%, p Citation Format: Matthew D. Wright, Marcus S. Dempster, Ayat ElSherif, Daniela Cocco, Stephanie A. Valente, Hong Li, Megan L. Kruse. Comparison of clinical features and outcomes for pleomorphic invasive lobular carcinoma vs. non-pleomorphic invasive lobular carcinoma [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P1-02-08.

Invasive lobular carcinoma (ILC) is thought be a unique entity with higher rates of multifocal/multicentric and bilateral disease. This study aimed to evaluate the true extent of the disease, risk of bilaterality, lymph node involvement, and impact of preoperative imaging to help guide surgical decision making.A retrospective analysis identified patients treated for ILC between 2004 and 2017. Clinical staging and pathologic results were compared. Follow-up details including local recurrence, contralateral breast cancer (CBC), and survival outcomes were evaluated.The study identified 692 patients with ILC, including 43 patients (6%) with a diagnosis of CBC and 232 patients (33%) with a diagnosis of multifocal/multicentric disease at presentation. Preoperative magnetic resonance imaging (MRI) led to an identification of additional disease in 20% of the patients. Preoperative MRI resulted in a more accurate prediction of tumor size staging but did not improve the discordance between clinical and pathologic nodal staging. Overall, the rate of imaging occult lymph node disease was 24%. At the 6-year follow-up evaluation, a local recurrence had developed in 2.3%, a CBC in 2.3, and a distant metastasis in 9.4% of the patients. The overall survival rate was 96% at 3 years and 91% at 5 years.Invasive lobular carcinoma is a distinct subset of cancer that poses a diagnostic staging challenge. The results of this study favor MRI for accurate tumor staging and for improving detection of multicentricity and bilaterality. However, clinicians should be aware of the higher likelihood of occult lymph node involvement with ILC and subsequent early metastasis.

Introduction: Cyclin-dependent kinase (CDK) 4/6 inhibitors have altered the standard-of-care treatment for patients with ER-positive, HER2-negative metastatic breast cancer. One such inhibitor, abe...

Airborne particulate matter is known to be deleterious to human health and exceeds exposure limits in many large cities. Some heavy metals and metalloids are known carcinogens and have been measured as constituents of PM in Bangkok air. There is growing interest in the sub-micron and ultrafine (< 100 nm) fractions due to their deeper penetration in the lung. Identifying distribution of metals over the size range can provide information on the metals source as well as providing information on the likely exposure to those particles.Three sites, owned and managed by the Thailand Pollution Control Department, were identified to provide contrasting particulate samples in a measurement campaign during 2018. The Ayutthaya site was located within the grounds of a school, 80 km to the north of Bangkok. The site was chosen as concentrations due to city traffic would be lower and could be considered a reference site. The Bang Phli site was situated in an industrial area 50 km to the south-east of Bangkok, in an area near industry. The Chok Chai site was in central Bangkok near to a busy road.At each site, three 3-day weekend and 3-day weekday gravimetric samples of size differentiated mass were drawn using an Electrical Low Pressure Impactor (ELPI; Dekati, Finland) over 12 size fractions in six different study visits. These were chosen to enable three measurements over the rainy season and three in the dry season. Each size fraction was weighed and then analysed by inductively coupled plasma mass spectroscopy to find the concentration of 17 elements (Mg, Al, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Mo, Cd, Sb, Ba and Pb). The ELPI also measured particle number concentration at 1 Hz. The number concentration of aerosol was highest in the Chok Chai roadside site, and lowest in the Ayutthaya background site. Al concentration was the highest in all three locations, with an average concentration over all measurements of 1909, 1012 and 1576 ng m-3 in Ayutthaya, Bang Phli and Chok Chai respectively. Concentrations of Al, Cr, Mg and Fe were typically higher than 100 ng m-3 in all sites, Cu and Zn higher than 10 ng m-3 and the rest lower.The shape of the metal distributions was consistent across all three sites for specific metals. Mg, Al, Cr, Mo, Ni and Cu could be described as having a flat distribution across all measured size distributions V, Mn, Cd, Sb, Pb, Zn As and Se had a peak in the sub-micron range, while Fe, Ba and Co peaked above 1 µm.Some seasonal effects could be seen across all three locations, these included an increase in Al, Cr and Fe during four measurements in dry season (November, 2018). This was particularly observed at Ayutthaya, where total measurements of Al were between 4862 and 5961 ng m-3, when all other measurements were between 98 and 264 ng m-3, suggesting a strong local source.

Background: Invasive lobular carcinoma (ILC) has increased rates of multifocal, multicentric, and bilateral disease. Despite high sensitivity in detection of ILC, preoperative breast MRI is not routinely done. Additional findings requiring biopsy may be necessary, which would possibly delay time to treatment (TTT). Increased TTT is associated with increased risk of mortality in early stage breast cancer. This study investigates the effect of preoperative MRI on TTT in ILC. Methods: A retrospective study utilizing an institutional database identified patients with ILC treated from 2004-2017. Patient and disease characteristics were recorded, including preoperative breast imaging modalities, new findings on preoperative breast MRI, and dates of treatment. Patients who had surgery were studied and separated into four groups: no MRI (No-MRI), MRI without new lesion (MRI-NNL), MRI with new lesion not biopsied (MRI-NL-NB), and MRI with new lesion that was biopsied (MRI-NL-B). TTT was defined as days from diagnosis to surgical management. Results: Of the total 691 patients, 452 (65.4%) received a preoperative MRI. Preoperative MRI was more likely among younger patients (mean age 58.5 vs. 67.4 years old, p Citation Format: Matthew D. Wright, Marcus S. Dempster, Ayat ElSherif, Daniela Cocco, Stephanie A. Valente, Hong Li, Megan L. Kruse. Assessing the impact of preoperative breast MRI on time to treatment for invasive lobular carcinoma [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P3-01-25.

Objective:To describe long-term outcomes of children with early-infantile Krabbe disease who underwent hematopoietic stem cell transplantation (HSCT) in the first 7 weeks of life.Methods:In this prospective longitudinal study, evaluations performed at baseline and follow-up included brain imaging, neurodiagnostic tests, and neurobehavioral evaluations.Results:Of the 18 patients in this study (11 girls, 7 boys; mean follow-up 9.5 years, range 4–15), 5 died (3 of peritransplant complications, 1 of a surgical complication unrelated to Krabbe disease, 1 of disease progression). One of the surviving patients has normal cognitive function and 10 continue to develop cognitive skills at a slightly slower rate than normal. All surviving patients continue to gain receptive language skills, with 7 falling within the normal range. Ten patients receive speech therapy, and 2 of these patients require augmentative communication devices. Gross motor development varies widely, but 3 patients can walk independently, and 7 walk with assistive devices. Spasticity ranges from mild to severe, and 12 patients wear orthotics. Fine motor skills are generally preserved. Brain myelination and atrophy stabilized in 8 patients, improved in 4 patients, and worsened in 1 patient. Nerve conduction velocities initially improved but continue to be abnormal in most patients.Conclusions:The surviving patients function at a much higher level than untreated children or symptomatic children who underwent HSCT. These results show that early HSCT changes the natural history of this disease by improving both lifespan and functional abilities.Classification of evidence:This study provides Class IV evidence that for children with early-infantile Krabbe disease, early HSCT improves lifespan and functional abilities.

Nanoparticles have been incorporated into a range of consumer spray products, providing the potential for inadvertent inhalation by users and bystanders. The levels and characteristics of nanoparticle inhalation exposures arising from the use of such products are important inputs to risk assessments and informing dose regimes for in vitro and in vivo studies investigating hazard potentials. To date, only a small number of studies have been undertaken to explore both the aerosols generated from such products and the metal nanoparticles within them. The objective of the current study was to add to the limited data in this field by investigating a range of nano-containing spray products available within the UK. Six products were selected and the nanoparticles characterised using a combination of techniques, including: inductively coupled plasma mass spectrometry (ICP-MS), dynamic light scattering (DLS), nanoparticle tracking analysis (NTA), transmission electron microscopy energy-dispersive X-ray spectroscopy (TEM-EDX) and single particle ICP-MS (spICP-MS). The aerosol produced by these products, when sprayed within a glovebox, was characterised by scanning mobility particle sizer (SMPS) and an aerodynamic particle sizer (APS). A cascade impactor with thirteen stages (NanoMOUDI) was used with one product to generate information on the size specific nanoparticle elemental distribution within the aerosol. The results demonstrated the presence of solid nanoparticles (silver, gold or silica) in each of the products at low concentrations (, Graphical abstract Image 1, Highlights • Nanomaterials (Ag, Au, silica) characterised in 6 consumer spray products. • Multi-method analytical approach allowed characterisation of particles and aerosols. • Large variations in aerosol mass and number concentrations across the products. • Non-uniform distribution of nanoparticles across aerosol particle size distribution.

Background Various mechanisms have been postulated to explain how electric fields emitted by high voltage overhead power lines, and the charged ions they produce, might be associated with possible adult cancer risk, but this has not previously been systematically explored in large scale epidemiological research. Methods We investigated risks of adult cancers in relation to modelled air ion density (per cm3) within 600 m (focusing analysis on mouth, lung, respiratory), and calculated electric field within 25 m (focusing analysis on non-melanoma skin), of high voltage overhead power lines in England and Wales, 1974–2008. Results With adjustment for age, sex, deprivation and rurality, odds ratios (OR) in the highest fifth of net air ion density (0.504–1) compared with the lowest (0–0.1879) ranged from 0.94 [95% confidence interval (CI) 0.82–1.08] for mouth cancers to 1.03 (95% CI 0.97–1.09) for respiratory system cancers, with no trends in risk. The pattern of cancer risk was similar using corona ion estimates from an alternative model proposed by others. For keratinocyte carcinoma, adjusted OR in the highest (1.06–4.11 kV/m) compared with the lowest ( Conclusions Our results do not provide evidence to support hypotheses that air ion density or electric fields in the vicinity of power lines are associated with cancer risk in adults.

Urban aerosol is a growing concern for people living within cities; aerosol have been implicated in many ill health conditions, including that of the lung and of the heart. Atmospheric potential gradient is a consequence of charge carried to the ionosphere through thunderstorms, and its value depends on highly electrically mobile ion concentrations, hence local conductivity of the air. Ions attach to aerosol in the atmosphere, reducing their mobility and therefore increasing the potential gradient, and so potential gradient measurements have been suggested as a proxy for aerosol measurements. Particle number count, size distribution and potential gradient were measured for two campaigns in Manchester, U.K., and one campaign in Bristol, U.K. Using a factor based on size distribution to account for preferential attachment at larger sizes provided the best relationship with potential gradient, but particle count alone showed a weaker, but similar relationship. The increase in particle count caused by annual bonfire and fireworks celebrations (November) was evidenced in both potential gradient and particle numbers. Daily regression or correlation did not show a consistent relationship. In the larger Bristol data set, increasing humidity led to a reduction of potential gradient, while increasing particle number led to an increase.

People spend the majority of their time indoors and therefore the quality of indoor air is worthy of investigation; indoor air quality is affected by indoor sources of pollutants and from pollutants entering buildings from outdoors. In this study, unique perfluorocarbon tracers were released in five experiments at a 100 m and ~2 km distance from a large university building in Manchester, UK and tracer was also released inside the building to measure the amount of outdoor material penetrating into buildings and the flow of material within the building itself. Air samples of the tracer were taken in several rooms within the building, and a CO2 tracer was used within the building to estimate air-exchange rates. Air-exchange rates were found to vary between 0.57 and 10.90 per hour. Indoor perfluorocarbon tracer concentrations were paired to outdoor tracer concentrations, and in-out ratios were found to vary between 0.01 and 3.6. The largest room with the lowest air-exchange rate exhibited elevated tracer concentrations for over 60 min after the release had finished, but generally had the lowest concentrations, the room with the highest ventilation rates had the highest concentration over 30 min, but the peak decayed more rapidly. Tracer concentrations indoors compared to outdoors imply that pollutants remain within buildings after they have cleared outside, which must be considered when evaluating human exposure to outdoor pollutants.

Corona ions produced by high-voltage power lines (HVPLs) can alter the nearby electrical environment, potentially increasing aerosol charge levels downwind. However, there is a lack of knowledge concerning the concentration and mobility of ions from AC HVPLs and their dispersion away from the line. We present ion concentration and mobility measurements made near AC HVPLs in South-West England. Examples of typical mobility spectra are shown highlighting features commonly observed. Corona was observed during 33 of 46 measurements, at 9 of 11 sites, with positive or ‘bipolar’ (both polarities) ion production commonly seen. Ion production usually increases atmospheric concentrations by only a modest amount, but extreme cases can enhance concentration by an order of magnitude or more. A polarity imbalance is required to increase aerosol charge via ion attachment; this was observed on 15 of 24 days when positive corona was observed, but was not seen for negative ions. Ion mobility was higher downwind compared with upwind for both ion polarities, but the increase was not statistically significant. Future work should focus on identifying and characterising ‘heavy-producing’ HVPLs, and obtaining results in conditions which may favour negative ion production e.g. high humidity, inclement weather or during nighttime.

Scanning or Sequential Mobility Particle Sizers (SMPS) are commonly used to obtain number size distributions (NSD) for submicron aerosols. In SMPS data inversion, correction for particle multiple-charging typically utilises data obtained at earlier times, therefore there is potential for error if concentration varies over the cycle time. We examine this error by using roadside experimental data to define simulated SMPS response distributions, including a time-varying transient peak due to a particle influx event, for input to inversion procedures. Because this distribution is specified for all times, the correct multiple-charging contributions can be used in data inversion. The results are compared with NSD obtained using a standard algorithm. We show that the net effect is to underestimate the true concentration, especially for diameters 80−200 nm (for the instrumentation studied here). For parameters typical of observed roadside transient events, errors in total concentration are ~2%, with up to ~8% error for concentration at individual diameters, and in all but the most extreme cases are less than typical experimental uncertainty estimates for SMPS instruments at roadside sites. Many previously published roadside size distributions may be affected, and for only a modest improvement in time resolution the effect may be exacerbated. The error introduced for given particle influx characteristics (which can be determined experimentally in future work and may be estimated for previous works) and for different instruments can be easily evaluated.

A relationship between Trace Gases (TG), NO x , SO 2 , O 3 , and the Atmospheric Electric Potential Gradient (PG), through Ion/Particulate Matter (PM) interaction, is established in the urban environment of the city of Lisbon (Portugal). Analysis was restricted to 1988–1990, when simultaneous measurements of PG and TG were taken. Reasonable linear relationships between PG and TG concentrations have been found. A formulation relating PG with TG concentrations allows the estimation of constants of proportionally between TG-PM to be ∼50 cm −3 ppb −1 ; which are similar to the values found in direct TG-PM measurements in UK cities, validating the present results.

Simultaneous ion concentration and potential gradient measurements were made at AC high voltage power lines using ion mobility spectrometers and electric field mills. A significant ( p

A portable technique is presented for rapid estimation of the charge distribution of submicron aerosols under atmospheric conditions, using two Differential Mobility Analyzer (DMA) systems in parallel. Simultaneous measurement of the aerosol mobility and size distributions are made by using one DMA with a neutralizer and the other without. An estimate of the aerosol charge is obtained by a fitting procedure, in which the size distribution and an expression for the charge distribution are used to calculate the mobility distribution of the sample. The parameters in the theoretical charge distribution are varied iteratively until the calculated and measured mobility distributions match. Validation was undertaken with separate measurements of ion mobility and concentration used in the charging expression. Results are presented for ambient indoor air, unipolar ion production by an ionizer and downwind of a high-voltage overhead AC powerline.

The characteristics of small-ions and aerosols in the diameter range 0.4 nm to 1.1 μm, produced during burning of paraffin wax tea-light candles, were investigated using a custom-built aspiration condenser ion mobility spectrometer (ACIMS) and a sequential mobility particle sizer and counter (SMPS+C) system. Peaks in the number concentration were observed at diameters 10–30 nm and 100–300 nm, consistent with “normal” and “sooting” burn modes. In addition, a smaller mode in the size range 2.5–9 nm was observed, interpreted as a soot-precursor species. When a fan was placed behind the burning candle a “modified small-ion” signal was seen at sizes 1.1–2.0 nm. This was not observed without the fan present or when a lamp chimney was used. During burning, aerosol concentration was elevated and small-ion counts were low. However after extinction of the flame, this trend was reversed and the number of small-ions increased to levels higher than those observed prior to burning, remaining so for several hours.

The 13C NMR spectroscopy of armchair and zigzag single-walled carbon nanotubes has been investigated theoretically. Spectra for (4,4), (5,5), (6,6), (6,0), (9,0), and (10,0) nanotubes have been simulated based on ab initio calculations of model systems. The calculations predict a dominant band arising from the carbon atoms in the "tube" with smaller peaks at higher chemical shifts arising from the carbon atoms of the caps. The dominant band lies in the range of 128 and 138 ppm. Its position depends weakly on the length, width, and chirality of the tubes. The calculations demonstrate how structural information may be gleaned from relatively low-resolution nanotube 13C NMR spectra.

A simple formulation is developed to model the influence of the aerosol hygroscopic growth in the dependence of the atmospheric electric field measurements with relative humidity. The formulation uses the Petters and Kreidenweis׳s model for the hygroscopic growth factor of aerosols with relative humidity and assumes that the ion–aerosol attachment coefficient is linearly proportional to the particle radius according to Gunn׳s calculation. A formula which describes the atmospheric electric field increase with relative humidity in the regime expected for the aerosols to grow hygroscopically is found; between 60% and 90%. It also relates the microphysical parameter of aerosol hygroscopicity, κ , with the macrophysical measure of the atmospheric electric field. Historical data of atmospheric electric field and relative humidity recorded in the meteorological station of Portela (near Lisbon airport, Portugal) are used to fit the model. The electrical measurements were done with a Benndorf electrograph and the 1980–1990 period was considered. Due to the high pollution levels the atmospheric electric field measurements were divided in four wind sectors, NW, NE, SE, and SW. The sector least affected by pollutant aerosols, NW, was used in the fitting and the goodness found is r 2 ~0.97, the aerosol concentration number is ~3280 cm −3 and the hygroscopic growth parameter κ ~0.094. These are very reasonable values consistent with an urban environment, which typically has high aerosol number concentration with small hygroscopicity. The limitations of the model are presented throughout the sections.

Atmospheric electric field measurements (potential gradient, PG) were retrieved in the urban environment of the city of Lisbon (Portugal). The measurements were performed with a Benndorf electrograph at the Portela Meteorological station in the suburbs of the city (NE from the centre). The period of 1980 to 1990 is considered here. According to wind direction, different content and types of ions and aerosols arrive at the measurement site causing significant variations to the PG. To the south there are significant pollution sources while to the north such sources are scarcer . The Iberian Peninsula is found east of the station and the Atlantic Ocean covers the western sector, Wind directions are divided in four sectors: i) NW: 270º ≤ θ ≤ 360º; ii) NE: 0 ≤ θ ≤ 90º; iii) SE: 90 ≤ θ ≤ 180º; iv) SW: 180º ≤ θ ≤ 270º. Analysis of weekly cycle, caused by anthropogenic pollution related with urban activity, was undertaken for each wind sector. NW sector has been shown to be less affected by this cycle, which is attributed to the effect of marine air. The daily variation of NE sector for weekends reveals a similar behaviour to the Carnegie curve, which corresponds to a clean air daily variation of PG, following universal time, independent of measurement site.

Corona ionisation from AC HV power lines (HVPL) can release ions into the environment, which have the potential to electrically charge pollutant aerosol in the atmosphere. It has been hypothesised that these charged particles have an enhanced probability of being deposited in human airways upon inhalation due to electrostatic attraction by image charge within the lung, with implications for human health. Carbonaceous aerosol particles from a Technegas generator were artificially charge-enhanced using a corona charger. Once generated, particles were passed through the charger, which was either on or off, and stored in a 15 litre conducting bag for ~20 minutes to observe size and charge distribution changes over time. Charge states were estimated using two Sequential Mobility Particle Sizers measuring the size and mobility distributions. Charge-neutral particles were measured 7 times and positive particles 9 times, the average charge-neutral value of x was 1.00 (sd = 0.06) while the average positive value was 4.60 (0.72). The system will be used to generate positive or charge neutral particles for delivery to human volunteers in an inhalation study to assess the impact of charge on ultrafine (size < 100 nm) particle deposition.

To understand the influence of corona ion emission on the atmospheric electrical field, measurements were made near to two AC high voltage power lines. A JCI 131 field-mill recorded the atmospheric electric field over one year. Meteorological measurements were also taken. The data series is divided in four zones (dependent on wind direction): whole zones, Z0; zone 1, Z1; zone 2, Z2; zone 3, Z3. Z3 is the least affected by corona ion emission and for that reason it is used as a reference against Z1 and Z2, which are strongly influenced by this phenomena. Analysis was undertaken for all weather days and dry days only. The Lomb-Scargle strategy developed for unevenly spaced time-series is used to calculate the spectral response of the aforementioned zones. Only frequencies above 1 minute are considered.