Birch pollen, air pollution and their interactive effects on airway symptoms and peak expiratory flow in allergic asthma during pollen season - a panel study in Northern and Southern Sweden.

BACKGROUND: Evidence of the role of interactions between air pollution and pollen exposure in subjects with allergic asthma is limited and need further exploration to promote adequate preventive measures. The objective of this study was to assess effects of exposure to ambient air pollution and birch pollen on exacerbation of respiratory symptoms in subjects with asthma and allergy to birch. METHODS: Thirty-seven subjects from two Swedish cities (Gothenburg and Umeå) with large variation in exposure to both birch-pollen and air pollutants, participated in the study. All subjects had confirmed allergy to birch and self-reported physician-diagnosed asthma. The subjects recorded respiratory symptoms such as rhinitis or eye irritation, dry cough, dyspnoea, the use of any asthma or allergy medication and peak respiratory flow (PEF), daily for five consecutive weeks during two separate pollen seasons and a control season without pollen. Nitrogen oxides (NOx), ozone (O3), particulate matter (PM2.5), birch pollen counts, and meteorological data were obtained from an urban background monitoring stations in the study city centres. The data were analysed using linear mixed effects models. RESULTS: During pollen seasons all symptoms and medication use were higher, and PEF was reduced in the subjects. In regression analysis, exposure to pollen at lags 0 to 2 days, and lags 0 to 6 days was associated with increased ORs of symptoms and decreased RRs for PEF. Pollen and air pollution interacted in some cases; during low pollen exposure, there were no associations between air pollution and symptoms, but during high pollen exposure, O3 concentrations were associated with increased OR of rhinitis or eye irritation, and PM2.5 concentrations were associated with increased ORs of rhinitis or eye irritation, dyspnea and increased use of allergy medication. CONCLUSIONS: Pollen and air pollutants interacted to increase the effect of air pollution on respiratory symptoms in allergic asthma. Implementing the results from this study, advisories for individuals with allergic asthma could be improved, minimizing the morbidities associated with the condition.

Occupational exposure to noise and cold environment and the risk of death due to myocardial infarction and stroke.

PURPOSE: The present study examined a possible association between occupational exposure to noise, working and living in cold conditions, and the risk of mortality in myocardial infarction and stroke. METHODS: The present cohort study consists of 194,501 workers in the Swedish construction industry that participated in health examinations between 1971 and 1993. Noise exposure was defined on a job-exposure matrix based on a survey of the working conditions carried out during the mid 1970s. All workers were categorised into three main regions of Sweden, differing in temperature: Reference (Götaland), colder (Svealand), and coldest (Norrland). Relative risks (RR) were analysed by negative binomial regression adjusting for age, BMI, and smoking habits. RESULTS: Moderate and high noise exposure was associated with increased risk of myocardial infarction (RR 1.10-1.13 with 95% CI over unit) and stroke mortality (RR 1.15 to 1.19 with 95% CI over unit). There was an increased risk for myocardial infarction (RR 1.10, 95% CI 1.01-1.20), but not for stroke mortality (RR 1.09, 95% CI 0.94-1.25) associated with living and working in the coldest region. There was an interaction on the risk of myocardial infarction mortality between different regions and noise exposure (p = 0.016), but not for stroke mortality (p = 0.88). CONCLUSIONS: The study indicates an interaction between working at hazardous noise levels and living and working in cold conditions for increased mortality in myocardial infarction.

Occupational biomechanical risk factors for radial nerve entrapment in a 13-year prospective study among male construction workers.

OBJECTIVES: The aim was to assess the association between occupational biomechanical exposure and the occurrence of radial nerve entrapment (RNE) in construction workers over a 13-year follow-up period. METHODS: A cohort of 229 707 male construction workers who participated in a national occupational health surveillance programme (1971-1993) was examined prospectively (2001-2013) for RNE. Height, weight, age, smoking status and job title (construction trade) were obtained on health examination. RNE case status was defined by surgical release of RNE, with data from the Swedish national registry for out-patient surgery records. A job exposure matrix was developed, and biomechanical exposure estimates were assigned according to job title. Highly correlated exposures were summed into biomechanical exposure scores. Negative binomial models were used to estimate the relative risks (RR) (incidence rate ratios) of RNE surgical release for the biomechanical factors and exposure sum scores. Predicted incidence was assessed for each exposure score modelled as a continuous variable to assess exposure-response relationships. RESULTS: The total incidence rate of surgically treated RNE over the 13-year observation period was 3.53 cases per 100 000 person-years. There were 92 cases with occupational information. Increased risk for RNE was seen in workers with elevated hand-grip forces (RR=1.79, 95% CI 0.97 to 3.28) and exposure to hand-arm vibration (RR=1.47, 95% CI 1.08 to 2.00). CONCLUSIONS: Occupational exposure to forceful handgrip work and vibration increased the risk for surgical treatment of RNE.

Air pollution and incidence of cancers of the stomach and the upper aerodigestive tract in the European Study of Cohorts for Air Pollution Effects (ESCAPE).

Air pollution has been classified as carcinogenic to humans. However, to date little is known about the relevance for cancers of the stomach and upper aerodigestive tract (UADT). We investigated the association of long-term exposure to ambient air pollution with incidence of gastric and UADT cancer in 11 European cohorts. Air pollution exposure was assigned by land-use regression models for particulate matter (PM) below 10 µm (PM10 ), below 2.5 µm (PM2.5 ), between 2.5 and 10 µm (PMcoarse ), PM2.5 absorbance and nitrogen oxides (NO2 and NOX ) as well as approximated by traffic indicators. Cox regression models with adjustment for potential confounders were used for cohort-specific analyses. Combined estimates were determined with random effects meta-analyses. During average follow-up of 14.1 years of 305,551 individuals, 744 incident cases of gastric cancer and 933 of UADT cancer occurred. The hazard ratio for an increase of 5 µg/m3 of PM2.5 was 1.38 (95% CI 0.99; 1.92) for gastric and 1.05 (95% CI 0.62; 1.77) for UADT cancers. No associations were found for any of the other exposures considered. Adjustment for additional confounders and restriction to study participants with stable addresses did not influence markedly the effect estimate for PM2.5 and gastric cancer. Higher estimated risks of gastric cancer associated with PM2.5 was found in men (HR 1.98 [1.30; 3.01]) as compared to women (HR 0.85 [0.5; 1.45]). This large multicentre cohort study shows an association between long-term exposure to PM2.5 and gastric cancer, but not UADT cancers, suggesting that air pollution may contribute to gastric cancer risk.

Commissioning and first-year operational results of the MAX†IV 3†GeV ring.

The MAX IV 3 GeV electron storage ring in Lund, Sweden, is the first of a new generation of light sources to make use of the multibend-achromat lattice (MBA) to achieve ultralow emitance and hence ultrahigh brightness and transverse coherence. The conceptual basis of the MAX IV 3 GeV ring project combines a robust lattice design with a number of innovative engineering choices: compact, multifunctional magnet blocks, narrow low-conductance NEG-coated copper vacuum chambers and a 100 MHz radio-frequency system with passively operated third-harmonic cavities for bunch lengthening. In this paper, commissioning and first-year operational results of the MAX IV 3 GeV ring are presented, highlighting those aspects that are believed to be most relevant for future MBA-based storage rings. The commissioning experience of the MAX IV 3 GeV ring offers in this way an opportunity for validation of concepts that are likely to be essential ingredients of future diffraction-limited light sources.

Childhood asthma and smoking exposures before conception-A three-generational cohort study.

BACKGROUND: Some human and animal studies have recently shown that maternal grandmother's smoking during pregnancy increases the risk of asthma in the grandchildren. We have investigated whether sex of the exposed parent and/or grandchild modifies the association between grandmaternal smoking and grandchild asthma. METHODS: We formed a cohort study based on linkage of national registries with prospectively collected data over three generations. Smoking habits in early pregnancy were registered since 1982 and purchases of prescribed medication since 2005. In all, 10 329 children born since 2005 had information on maternal and grandmaternal smoking on both sides and were followed from birth up to 6 years of age. Ages when medication was purchased were used to classify the cohort into never, early transient (0-3 years), early persistent (0-3 and 4-6 years), and late-onset (4-6 years) phenotypes of childhood asthma. RESULTS: Maternal grandmother's smoking was associated with an increased odds of early persistent asthma after adjustment for maternal smoking and other confounders (odds ratio 1.29, 95% confidence interval 1.10-1.51). Grandchild sex did not modify the association. Paternal grandmother's smoking was not associated with any of the asthma phenotypes. CONCLUSION: Maternal but not paternal exposure to nicotine before conception was related to an increased risk of early persistent childhood asthma, but not other asthma phenotypes. Our findings are possibly consistent with a sex-specific mode of epigenetic transfer.

Outdoor air pollution and risk for kidney parenchyma cancer in 14 European cohorts.

Several studies have indicated weakly increased risk for kidney cancer among occupational groups exposed to gasoline vapors, engine exhaust, polycyclic aromatic hydrocarbons and other air pollutants, although not consistently. It was the aim to investigate possible associations between outdoor air pollution at the residence and the incidence of kidney parenchyma cancer in the general population. We used data from 14 European cohorts from the ESCAPE study. We geocoded and assessed air pollution concentrations at baseline addresses by land-use regression models for particulate matter (PM10 , PM2.5 , PMcoarse , PM2.5 absorbance (soot)) and nitrogen oxides (NO2 , NOx ), and collected data on traffic. We used Cox regression models with adjustment for potential confounders for cohort-specific analyses and random effects models for meta-analyses to calculate summary hazard ratios (HRs). The 289,002 cohort members contributed 4,111,908 person-years at risk. During follow-up (mean 14.2 years) 697 incident cancers of the kidney parenchyma were diagnosed. The meta-analyses showed higher HRs in association with higher PM concentration, e.g. HR = 1.57 (95%CI: 0.81-3.01) per 5 µg/m3 PM2.5 and HR = 1.36 (95%CI: 0.84-2.19) per 10-5 m-1 PM2.5 absorbance, albeit never statistically significant. The HRs in association with nitrogen oxides and traffic density on the nearest street were slightly above one. Sensitivity analyses among participants who did not change residence during follow-up showed stronger associations, but none were statistically significant. Our study provides suggestive evidence that exposure to outdoor PM at the residence may be associated with higher risk for kidney parenchyma cancer; the results should be interpreted cautiously as associations may be due to chance.

Most patients with long-chain 3-hydroxyacyl-CoA dehydrogenase deficiency develop pathological or subnormal retinal function.

AIM: There have been few studies on long-term electroretinographic findings in patients with long-chain 3-hydroxyacyl-CoA dehydrogenase deficiency (LCHADD). This study correlated long-term electroretinographic findings with age, metabolic control and clinical symptoms. METHODS: We examined 12 Swedish patients with LCHADD. Visual acuity testing, fundus examinations, optical coherence tomography and electroretinography were performed. The results were correlated to age, the levels of 3-hydroxyacylcarnitine and acylcarnitine and clinical metabolic control. RESULTS: Blindness or moderate visual impairment was found in two patients. Retinal pigmentation, atrophy and fibrosis were present in 11, seven and one of the patients, respectively, and optical coherence tomography showed retinal thinning in three of the six patients examined. Electroretinography was performed on 11 of the 12 patients. It was pathological, with reduced rod and cone responses, in five patients, subnormal in four and was related to poor clinical metabolic control and severe neonatal symptoms. Repeated electroretinographies revealed reduced function with increasing age. CONCLUSION: More than 80% of the LCHADD patients developed pathological or subnormal retinal function. This was more pronounced in patients with neonatal symptoms, but ameliorated by strict dietary treatment. Annual ophthalmological follow-ups, with electroretinography every second or third year, are recommended.

Short-term exposure to ozone and levels of exhaled nitric oxide.

BACKGROUND: Adverse effects of air pollution include respiratory inflammation. A few epidemiologic studies have shown elevations in the fraction of exhaled nitric oxide, a marker of airway inflammation, after exposure to traffic-related pollutants. METHODS: We examined whether short-term exposures to ozone (O3), oxides of nitrogen (NOx), or particulate matter <10 µm (PM10) were associated with proximal and distal airway inflammation. The study included 5841 randomly selected Swedish adults from 25 to 75 years of age. Fraction of exhaled nitrogen was measured at two flow rates: 50 ml/s representing the proximal airways and 270 ml/s representing the distal airways. Air pollution data were obtained from an urban monitoring site. We applied linear regression to estimate short-term associations of O3, NOx, and PM10 with fractions of exhaled NO at 50 and 270 ml/s. RESULTS: An interquartile range increase in 120-hour average O3 levels was associated with a 5.1% (95% confidence interval = 1.7% to 8.5%) higher level of fraction of exhaled NO at 270 ml/s and 3.6% (-0.4% to 3.4%) higher level of the fraction of exhaled NO at 50 ml/s. For NOx, a small effect was seen for the 24-hour average on the fraction of exhaled NO at 270 ml/s, while for PM10 no clear effects were seen. There was a tendency for a weaker effect of ozone and a stronger effect of NOx in subjects with asthma. CONCLUSIONS: Exposure to O3 was associated with a marker of distal airway inflammation, while the association was less obvious for inflammation of the proximal airways.

Long-term exposure to air pollution and cardiovascular mortality: an analysis of 22 European cohorts.

BACKGROUND: Air pollution has been associated with cardiovascular mortality, but it remains unclear as to whether specific pollutants are related to specific cardiovascular causes of death. Within the multicenter European Study of Cohorts for Air Pollution Effects (ESCAPE), we investigated the associations of long-term exposure to several air pollutants with all cardiovascular disease (CVD) mortality, as well as with specific cardiovascular causes of death. METHODS: Data from 22 European cohort studies were used. Using a standardized protocol, study area-specific air pollution exposure at the residential address was characterized as annual average concentrations of the following: nitrogen oxides (NO2 and NOx); particles with diameters of less than 2.5 µm (PM2.5), less than 10 µm (PM10), and 10 µm to 2.5 µm (PMcoarse); PM2.5 absorbance estimated by land-use regression models; and traffic indicators. We applied cohort-specific Cox proportional hazards models using a standardized protocol. Random-effects meta-analysis was used to obtain pooled effect estimates. RESULTS: The total study population consisted of 367,383 participants, with 9994 deaths from CVD (including 4,992 from ischemic heart disease, 2264 from myocardial infarction, and 2484 from cerebrovascular disease). All hazard ratios were approximately 1.0, except for particle mass and cerebrovascular disease mortality; for PM2.5, the hazard ratio was 1.21 (95% confidence interval = 0.87-1.69) per 5 µg/m and for PM10, 1.22 (0.91-1.63) per 10 µg/m. CONCLUSION: In a joint analysis of data from 22 European cohorts, most hazard ratios for the association of air pollutants with mortality from overall CVD and with specific CVDs were approximately 1.0, with the exception of particulate mass and cerebrovascular disease mortality for which there was suggestive evidence for an association.

Detection of active SARS-CoV-2 in cough aerosols from COVID-19 patients.

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is an airborne pathogen, but detection of infectious SARS-CoV-2 in air and in particular the introduction of the virus into the environment by different human expiratory manoeuvres is not well studied. OBJECTIVES: The aim of this study was to investigate the presence of SARS-CoV-2 in cough from coronavirus disease of 2019 (COVID-19) in-patients and to study contamination of the virus in the patient's environment. METHODS: Detection of SARS-CoV-2 in cough was analyzed by PCR, culture and imaging. Detection in cough was compared to presence of the virus in air and on surfaces from patient rooms. RESULTS: Twenty-five patients in 21 rooms were included in the study. SARS-CoV-2 RNA was found in cough aerosols from 16 out of 22 patients that produced voluntary cough. As demonstrated by plaque-forming unit assays, active virus was isolated from 11 of these 16 patients. Using mainly molecular detection, the virus was also found in air, on high-contact surfaces, and no-touch surfaces from the room of the COVID-19 patients. CONCLUSIONS: These results show that infectious SARS-CoV-2 circulating in air can originate from patient cough and should be considered against the risk of acquiring COVID-19 through inhalation.

Pollen exposure in pregnancy and infancy and risk of asthma hospitalisation - a register based cohort study.

BACKGROUND: A seasonal effect of month of birth and risk of allergic disease has been suggested by numerous studies. Few studies have directly measured pollen exposures at different points during pregnancy and in early life, and assessed their effects on risk of respiratory disease outcomes. METHODS: Pollen exposure was calculated for the first and last 12 weeks of pregnancy and the first 12 weeks of infancy for all children conceived by women residing in Stockholm, Sweden, between 1988 and 1995. Hospital admission data for respiratory conditions in the first year of life was also collected. RESULTS: Out of 110,381 children, 940 had been hospitalised for asthma by 12-months of age. Pollen levels showed both marked seasonal variations and between year differences. Exposure to high levels of pollen in the last 12 weeks of pregnancy was associated with an increased risk of asthma hospitalisation (aOR = 1.35, 95% CI = 1.07-1.71 for highest quartile versus remaining infants). Exposure to high levels of pollen in the first three months of life was associated with a reduced risk (aOR = 0.76, 95% CI = 0.59-0.98) but only in children of heavy smoking mothers. CONCLUSIONS: High levels of pollen exposure during late pregnancy were somewhat unexpectedly associated with an elevated risk of hospitalisation for asthma within the first year of life.

Validity of Three Survey Questions for Self-Assessed Sedentary Time.

Time spent in sedentary behavior (SB) has increased during the last decades. Accurate assessments are of importance when studying health consequences of SB. This study aimed to assess concurrent validity between three different questions for self-reported sitting and thigh worn accelerometer data. In total, 86 participants wore the ActivPAL accelerometer during three separate weeks, assessing sitting time with different questions each week. The questions used were Katzmarzyk, GIH stationary single-item question (SED-GIH), and a modified version of the single-item from IPAQ short form. In total 64, 57, and 55 participants provided valid accelerometer and questionnaire data at each time-point, respectively, and were included for analysis. Spearman and Pearson correlation was used to assess the validity. The three questions, Katzmarzyk, SED-GIH, and a modified question from IPAQ all showed a weak non-significant correlation to ActivPAL with r-values of 0.26, 0.25, and 0.19 respectively. For Katzmarzyk and SED-GIH, 50% and 37% reported correctly, respectively. For the modified IPAQ, 53% over-reported and 47% under-reported their sitting time. In line with previous research, our study shows poor validity for self-reported sitting-time. For future research, the use of sensor-based data on SB are of high importance.

Altered mitochondrial metabolism in peripheral blood cells from patients with inborn errors of ß-oxidation.

Inborn errors of mitochondrial fatty acid oxidation (FAO), such as medium-chain acyl-CoA dehydrogenase deficiency (MCAD) and very long-chain acyl-CoA dehydrogenase deficiency (VLCAD) affects cellular function and whole-body metabolism. Carnitine uptake deficiency (CUD) disturbs the transportation of fatty acids into the mitochondria, but when treated is a mild disease without significant effects on FAO. For improved clinical care of VLCAD in particular, estimation of FAO severity could be important. We have investigated whether the oxygen consumption rate (OCR) of peripheral blood mononuclear cells (PBMCs) obtained from patients with MCAD, VLCAD, and CUD can be used to study cellular metabolism in patients with FAO defects and to determine the severity of FAO impairment. PBMCs were isolated from patients with VLCAD (n = 9), MCAD (n = 5-7), and CUD (n = 5). OCR was measured within 6-hours of venous puncture using the Seahorse XFe96. The PBMCs were exposed to glucose alone or with caprylic acid (C8:0) or palmitic acid (C16:0). OCR was significantly lower in cells from patients with ß-oxidation deficiencies (MCAD and VLCAD) compared to CUD at basal conditions. When exposed to C16:0, OCR in VLCAD cells was unchanged, whereas OCR in MCAD cells increased but not to the levels observed in CUD. However, C8:0 did not increase OCR, as would be expected, in VLCAD cells. There was no clear relationship between clinical severity level and OCR. In patients with ß-oxidation deficiencies, changes of mitochondrial respiration in PBMCs are detectable, which indicate that PBMCs have translational potential for studies of ß-oxidation defects. However, further studies are warranted.

Very long-chain acyl-CoA dehydrogenase deficiency in a Swedish cohort: Clinical symptoms, newborn screening, enzyme activity, and genetics.

Very long-chain acyl-CoA dehydrogenase deficiency (VLCADD) is a recessive disorder of fatty acid beta-oxidation with variable phenotype. Patients may present during the neonatal period with lethal multi-organ failure or during adulthood with a myopathic phenotype. VLCADD is included in the Swedish newborn screening (NBS) program since 2010. The study describes the phenotype and biochemical findings in relation to the genotype, enzyme activity, and screening data in a Swedish cohort of pediatric patients with VLCADD. A total of 22 patients (20 diagnosed via NBS between 2010 and 2019, two diagnosed pre NBS) were included. Parameters analyzed were enzyme activity (palmitoyl CoA oxidation rate); ACADVL genotype; NBS results including Collaborative Laboratory Integrated Reports (CLIR) score; biochemical findings; treatment; clinical outcome. A clinical severity score (CSS) was compiled using treatment interventions and clinical symptoms. A possible correlation between CSS and VLCAD residual enzyme activity and NBS CLIR score was analyzed. The most common ACADVL variant (c.848T>C) was identified in 24/44 alleles. Five novel variants were detected. Clinical manifestations varied from asymptomatic to severe. There was a correlation between CSS, residual enzyme activity, and CLIR scores. Most patients diagnosed via NBS had less severe disease compared to those clinically diagnosed. In conclusion, the identified correlation between the NBS CLIR score, residual enzyme activity, and clinical outcome suggests that information available neonatally may aid in treatment decisions.

Early childhood exposure to ambient air pollution is associated with increased risk of paediatric asthma: An administrative cohort study from Stockholm, Sweden.

INTRODUCTION: Asthma is a complex, heterogeneous disease and one of the most common chronic diseases among children. Exposure to ambient air pollution in early life and childhood may influence asthma aetiology, but it is uncertain which specific components of air pollution and exposure windows are of importance. The role of socio-economic status (SES) is also unclear. The aims of the present study are, therefore, to investigate how various exposure windows of different pollutants affect risk-induced asthma in early life and to explore the possible effect SES has on that relationship. METHODS: The study population was constructed using register data on all singleton births in the greater Stockholm area between 2006 and 2013. Exposure to ambient black carbon (BC), fine particulate matter (PM2.5), primary organic carbon (pOC) secondary organic aerosols (SOA), secondary inorganic aerosols, and oxidative potential at the residential address was modelled as mean values for the entire pregnancy period, the first year of life and the first three years of life. Swedish national registers were used to define the outcome: asthma diagnosis assessed at hospital during the first six years of life. Hazard ratios (HRs) and their 95% confidence intervals (CIs) were modelled with Cox proportional hazards model with age as the underlying time-scale, adjusting for relevant potential confounding variables. RESULTS: An increased risk for developing childhood asthma was observed in association with exposure to PM2.5, pOC and SOA during the first three years of life. With an interquartile range increase in exposure, the HRs were 1.06 (95% CI: 1.01-1.10), 1.05 (95% CI: 1.02-1.09) and 1.02 (95% CI: 1.00-1.04), for PM2.5, pOC and SOA, respectively, in the fully adjusted models. Exposure during foetal life or the first year of life was not associated with asthma risk, and the other pollutants were not statistically significantly associated with increased risk. Furthermore, the increase in risk associated with PM2.5 and the components BC, pOC and SOA were stronger in areas with lower SES. CONCLUSION: Our results suggest that exposure to air pollution during the first three years of life may increase the risk for asthma in early childhood. The findings further imply a possible increased vulnerability to air pollution-attributed asthma among low SES children.

Productivity, Satisfaction, Work Environment and Health after Relocation to an Activity-Based Flex Office-The Active Office Design Study.

Implementation of activity-based flex offices (AFOs) are becoming increasingly common. The aim of this study was to evaluate the effects of an AFO on perceived productivity, satisfaction, work environment and health. Questionnaire data from the longitudinal, quasi-experimental Active Office Design Study was used. The study evaluates a public organization relocating staff to either an AFO or to cell offices. Measures from baseline, 6 and 18 months after relocation, were analyzed. Employees in the AFO experienced a decreased productivity and satisfaction with the office design. Lack of privacy as well as increased noise disturbance, less satisfaction with sit comfort and work posture were reported. Employees in the AFO with work tasks requiring a high degree of concentration experienced lower productivity while those with a high proportion of teamwork rated productivity to be continually high. No significant group differences were found between the two office types in general health, cognitive stress, salutogenic health indicators or pain in the neck, shoulder or back. The study highlights the importance of taking work characteristics into account in the planning and implementation process of an AFO. Flexible and interactive tasks seem more appropriate in an AFO, whereas individual tasks demanding concentration seem less fit.

Associations between Vehicle Exhaust Particles and Ozone at Home Address and Birth Weight.

We have studied the associations between exhaust particles and birth weight. Adjustments were made for ozone and potential confounding factors at the individual level. The study included all singletons conceived between August 2003 and February 2013 with mothers living in Greater Stockholm. We obtained record-based register data from the Swedish Medical Birth Register. Data concerning the parents were provided by Statistics Sweden. Exposure levels for nearly 187,000 pregnancies were calculated using a validated air quality dispersion model with input from a detailed emission database. A higher socioeconomic status was associated with higher levels of exhaust particles at the home address. In this region, with rather low air pollution levels, the associations between levels of exhaust particles and birth weight were negative for all three of the studied exposure windows (i.e., first and second trimester and full pregnancy). For the entire pregnancy, the linear decrease in birth weight was 7.5 grams (95% CI-12.0; -2.9) for an increase in exposure, corresponding to the inter quartile range (IQR = 209 ng/m3). We also found that the risk of being born small for gestational age increased with the level of exhaust particles in all three exposure windows, but these associations were not statistically significant.

Underlying Factors Explaining Physical Behaviors among Office Workers-An Exploratory Analysis.

Studies using technical measurements of physical behavior show wide interindividual variations. This study aimed to explore underlying factors related to sitting, standing and walking among office workers. Cross-sectional data for background characteristics, work-related variables, and device-based measures for sitting, standing and walking were collected among office workers in either a cell office or a flex office with activity-based work. Data were analyzed by Factor Analysis of Mixed Data (FAMD) and multiple robust linear regression. The FAMD resulted in the combination of underlying factors describing six character types. The (1) harmonic and healthy, (2) disabled with poor health, (3) manager that spend a lot of time in meetings and has very high workload, (4) engaged with high workload, (5) employee with creative and computer intense work, with high workload and, (6) employee with high BMI with creative and collaborative work. Regression analysis showed that the character type that was "engaged with high workload" sat more and stood less, while the character type with "high BMI and with creative and collaborative work" sat less. The results suggest that physical behavior among office workers is influenced by a complex combination of factors, which should be taken into account in the evaluation of future studies of larger cohorts.