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 (NO_x), ozone (O₃), particulate matter (PM_2.5), 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 PM_2.5 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.

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.

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 (PM_2.5), 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 PM_2.5, 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 PM_2.5, 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 PM_2.5 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.

Altered mitochondrial metabolism in peripheral blood cells from patients with inborn errors of β-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 β-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 β-oxidation deficiencies, changes of mitochondrial respiration in PBMCs are detectable, which indicate that PBMCs have translational potential for studies of β-oxidation defects. However, further studies are warranted.

Validity and reliability of the Swedish version of the Self-Efficacy for Managing Chronic Disease scale for individuals with systemic sclerosis

ObjectiveTo investigate aspects of validity and reliability of the Swedish version of the Self-Efficacy for Managing Chronic Disease (SEMCD-Swe) scale in systemic sclerosis (SSc).Method: A forward-backward translation procedure was used. Content validity was assessed through interviews with 11 people with SSc and 10 healthcare professionals. Construct validity, internal consistency, test-retest reliability, and floor and ceiling effects were evaluated in 104 SSc patients.Results: The content validity of the SEMCD-Swe was interpreted as satisfactory, but some adjustments were made to increase the understanding. Confirmatory factor analysis supported a single-factor structure. Moderate to strong correlations between the SEMCD-Swe and Scleroderma Health Assessment Questionnaire; Multidimensional Assessment of Fatigue; Patient Health Questionnaire-8 (r_s = -0.4 to -0.7), and RAND-36 subscales (r_s = 0.5 to 0.7) were found. Weak correlations were found between SEMCD-Swe and modified Rodnan skin score; and disease severity of peripheral vascular and lung (r_s = -0.1 to -0.2) and kidney (r_s = 0.1) systems (Medsger severity scale). Cronbach's alpha was sufficient (0.85) and corrected item-to-total correlations were good (≥ 0.50). The intraclass correlation coefficient for the total score was sufficient (0.82). No floor or ceiling effects were found.Conclusion: Support for construct validity was indicated, as the SEMCD-Swe in SSc show a single-factor structure and is more strongly associated with pain, fatigue, depressive symptoms, interferences with daily activities, disability, and quality of life than with disease severity. Our results also indicate support for content validity and reliability. However, the responsiveness of the SEMCD-Swe needs to be tested.

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.

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.

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.

Long-term exposure to ambient air pollution and incidence of brain tumor: the European Study of Cohorts for Air Pollution Effects (ESCAPE)

Background

Epidemiological evidence on the association between ambient air pollution and brain tumor risk is sparse and inconsistent.

Methods

In 12 cohorts from 6 European countries, individual estimates of annual mean air pollution levels at the baseline residence were estimated by standardized land-use regression models developed within the ESCAPE and TRANSPHORM projects: particulate matter (PM) ≤2.5, ≤10, and 2.5–10 μm in diameter (PM_2.5, PM₁₀, and PM_coarse), PM_2.5 absorbance, nitrogen oxides (NO₂ and NO_x) and elemental composition of PM. We estimated cohort-specific associations of air pollutant concentrations and traffic intensity with total, malignant, and nonmalignant brain tumor, in separate Cox regression models, adjusting for risk factors, and pooled cohort-specific estimates using random-effects meta-analyses.

Results

Of 282194 subjects from 12 cohorts, 466 developed malignant brain tumors during 12 years of follow-up. Six of the cohorts also had data on nonmalignant brain tumor, where among 106786 subjects, 366 developed brain tumor: 176 nonmalignant and 190 malignant. We found a positive, statistically nonsignificant association between malignant brain tumor and PM_2.5 absorbance (hazard ratio and 95% CI: 1.67; 0.89–3.14 per 10^–5/m³), and weak positive or null associations with the other pollutants. Hazard ratio for PM_2.5 absorbance (1.01; 0.38–2.71 per 10^–5/m³) and all other pollutants were lower for nonmalignant than for malignant brain tumors.

Conclusion

We found suggestive evidence of an association between long-term exposure to PM_2.5 absorbance indicating traffic-related air pollution and malignant brain tumors, and no association with overall or nonmalignant brain tumors.

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.

Occupational biomechanical risk factors for surgically treated ulnar nerve entrapment in a prospective study of male construction workers

Objectives The aim of this study was to determine the association between occupational biomechanical exposures and occurrence of surgically treated ulnar nerve entrapment (UNE). Methods A cohort of 229 689 male construction workers who participated in a national occupational health surveillance program (1971-1993) were examined prospectively over a 13-year case ascertainment period (2001-2013) for surgically treated UNE. Job title (construction trade), smoking status, height, weight and age were recorded on examination. Job titles were merged into occupational groups of workers performing similar work tasks and having similar training. Occupational biomechanical exposure estimates were assigned to each occupational group with a job exposure matrix (JEM) developed for the study. Negative binomial models were used to assess the relative risks for each biomechanical exposure and the sums of highly correlated biomechanical exposures. Surgical treatment of UNE was determined via a linkage with the Swedish Hospital Outpatient Surgery Register. Results There were 555 cases of surgically treated UNE within the cohort. Workers exposed to forceful hand-grip factors had a 1.4-fold higher relative risk (95% CI 1.18-1.63) of undergoing surgical treatment for UNE compared to unexposed workers. Occupational groups comprising workers exposed to forceful hand-grip work showed the highest risks for UNE and included concrete workers, floor layers, ground preparatory workers, rock blasters, and sheet-metal workers. Conclusion Forceful hand-grip work increases the risk for surgically treated ulnar nerve entrapment.

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.

Is There an Association Between Ambient Air Pollution and Bladder Cancer Incidence? Analysis of 15 European Cohorts

BACKGROUND

Ambient air pollution contains low concentrations of carcinogens implicated in the etiology of urinary bladder cancer (BC). Little is known about whether exposure to air pollution influences BC in the general population.

OBJECTIVE

To evaluate the association between long-term exposure to ambient air pollution and BC incidence.

DESIGN, SETTING, AND PARTICIPANTS

We obtained data from 15 population-based cohorts enrolled between 1985 and 2005 in eight European countries (N=303431; mean follow-up 14.1 yr). We estimated exposure to nitrogen oxides (NO2 and NOx), particulate matter (PM) with diameter <10μm (PM10), <2.5μm (PM2.5), between 2.5 and 10μm (PM2.5-10), PM2.5absorbance (soot), elemental constituents of PM, organic carbon, and traffic density at baseline home addresses using standardized land-use regression models from the European Study of Cohorts for Air Pollution Effects project.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

We used Cox proportional-hazards models with adjustment for potential confounders for cohort-specific analyses and meta-analyses to estimate summary hazard ratios (HRs) for BC incidence.

RESULTS AND LIMITATIONS

During follow-up, 943 incident BC cases were diagnosed. In the meta-analysis, none of the exposures were associated with BC risk. The summary HRs associated with a 10-μg/m3 increase in NO2 and 5-μg/m3 increase in PM2.5 were 0.98 (95% confidence interval [CI] 0.89-1.08) and 0.86 (95% CI 0.63-1.18), respectively. Limitations include the lack of information about lifetime exposure.

CONCLUSIONS

There was no evidence of an association between exposure to outdoor air pollution levels at place of residence and risk of BC.

PATIENT SUMMARY

We assessed the link between outdoor air pollution at place of residence and bladder cancer using the largest study population to date and extensive assessment of exposure and comprehensive data on personal risk factors such as smoking. We found no association between the levels of outdoor air pollution at place of residence and bladder cancer risk.

Long-Term Exposure to Ambient Air Pollution and Incidence of Postmenopausal Breast Cancer in 15 European Cohorts within the ESCAPE Project

BACKGROUND

Epidemiological evidence on the association between ambient air pollution and breast cancer risk is inconsistent.

OBJECTIVE

We examined the association between long-term exposure to ambient air pollution and incidence of postmenopausal breast cancer in European women.

METHODS

In 15 cohorts from nine European countries, individual estimates of air pollution levels at the residence were estimated by standardized land-use regression models developed within the European Study of Cohorts for Air Pollution Effects (ESCAPE) and Transport related Air Pollution and Health impacts – Integrated Methodologies for Assessing Particulate Matter (TRANSPHORM) projects: particulate matter (PM) ≤2.5μm, ≤10μm, and 2.5–10μm in diameter (PM2.5, PM10, and PMcoarse, respectively); PM2.5 absorbance; nitrogen oxides (NO2 and NOx); traffic intensity; and elemental composition of PM. We estimated cohort-specific associations between breast cancer and air pollutants using Cox regression models, adjusting for major lifestyle risk factors, and pooled cohort-specific estimates using random-effects meta-analyses.

RESULTS

Of 74,750 postmenopausal women included in the study, 3,612 developed breast cancer during 991,353 person-years of follow-up. We found positive and statistically insignificant associations between breast cancer and PM2.5 {hazard ratio (HR)=1.08 [95% confidence interval (CI): 0.77, 1.51] per 5 μg/m3}, PM10 [1.07 (95% CI: 0.89, 1.30) per 10 μg/m3], PMcoarse[1.20 (95% CI: 0.96, 1.49 per 5 μg/m3], and NO2 [1.02 (95% CI: 0.98, 1.07 per 10 μg/m3], and a statistically significant association with NOx [1.04 (95% CI: 1.00, 1.08) per 20 μg/m3, p=0.04].

CONCLUSIONS

We found suggestive evidence of an association between ambient air pollution and incidence of postmenopausal breast cancer in European women. https://doi.org/10.1289/EHP1742.

Grandmaternal smoking increases asthma risk in grandchildren: A nationwide Swedish cohort

BACKGROUND

There is growing interest in exposures prior to conception as possible risk factors for offspring asthma. Although partially supported by evidence from limited human studies, current evidence is inconsistent and based on recall of exposure status.

OBJECTIVE

We aimed to investigate grandmaternal smoking during pregnancy and the risk of asthma in grandchildren using prospectively collected population-based data.

METHODS

Information on grandmaternal and maternal smoking during pregnancy and grandchild use of asthma medications was collected from national Swedish registries. Associations between grandmaternal smoking during pregnancy (10-12 weeks) and asthma medication use in grandchildren were investigated using generalized estimating equations. Ages at which asthma medications were prescribed classified childhood asthma into never, early transient (0-3 years), late onset (3-6 years) and early persistent (0-3 and 3-6 years) phenotypes.

RESULTS

From 1982 to 1986, 44 583 grandmothers gave birth to 46 197 mothers, who gave birth to 66 271 grandchildren (born 1996-2010). Children aged 1-6 years had an increased asthma risk if their grandmothers had smoked during pregnancy, with a higher risk for more exposure (10+ cigs/d; adjusted OR 1.23; 1.17, 1.30). Maternal smoking did not modify this relationship.

CONCLUSIONS & CLINICAL RELEVANCE

Children had an increased risk of asthma in the first 6 years of life if their grandmothers smoked during early pregnancy, independent of maternal smoking. Importantly, this exhibited a dose-response relationship and was associated with a persistent childhood asthma phenotype. These findings support possible epigenetic transmission of risk from environmental exposures in previous generations.

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.

Traffic pollution at the home address and pregnancy outcomes in Stockholm, Sweden

BACKGROUND

For the past two decades, several studies have reported associations between elevated levels of ambient air pollution and adverse pregnancy outcomes, although with varying conclusions.

OBJECTIVES

To examine possible associations between the traffic pollution situation at the home address, for women who did not change address during pregnancy, and three types of pregnancy outcomes: spontaneous preterm delivery, children born small for gestational age (SGA) and pregnancy-induced hypertensive disorders.

METHODS

We used data for the Greater Stockholm Area from the Swedish Medical Birth Register to construct a cohort based on all pregnancies conceived between July 1997 and March 2006, n = 100 190. The pregnancy average nitrogen oxide, NOx, levels and annual mean daily vehicles at the home address were used as exposure variables. Mixed-model logistic regression was performed to assess any associations between exposure and outcome.

RESULTS

There was an association between elevated traffic pollution exposure during pregnancy and pregnancy-induced hypertensive disorders. A 10 µg/m(3) increase in the pregnancy average NOx level at the home address resulted in an OR of 1.17 (95% CI 1.10 to 1.26). The 2nd to 4th quartiles of NOx were all associated with an increased risk of SGA, but there was no difference in the risk estimate among the higher quartiles. There was a tendency of a higher risk of spontaneous preterm delivery in relation to higher levels of NOx. There was no evidence of an association between vehicle flow, the cruder indicator of traffic pollution, and the studied outcomes in this study.

CONCLUSIONS

In this large cohort, there was a fairly strong association between vehicle exhaust levels at the home address and pregnancy-induced hypertensive disorders, after adjustment for important risk factors.

Exposure to seasonal temperatures during the last month of gestation and the risk of preterm birth in Stockholm

Recent evidence from studies performed mainly in warm climates suggests an association between exposure to extreme temperatures late in pregnancy and an increased risk of preterm delivery. However, there have been fewer studies on the effect of low temperatures. The aim of this study is to explore the potential association between both heat and cold during late pregnancy and an increased risk of preterm birth in the northern location of Stockholm, Sweden. All singleton spontaneous births that took place in greater Stockholm (1998–2006) were included. Non-linear and delayed effects of mean temperature on the risk of preterm birth were explored through distributed lag non-linear models. Extreme and moderate heat and cold were estimated separately through quasi-Poisson regression analysis in two seasonal periods (heat in warm season, cold in cold season). The risk of preterm birth increased by 4%–5% when the mean temperature reached the 75th percentile (moderate heat) four weeks earlier (reference: the annual median value), with a maximum cumulative risk ratio of 2.50 (95% confidence interval: 1.02–6.15). Inconsistent associations were obtained for cold and extreme heat. Exposure to moderately high temperatures during late pregnancy might be associated with an increase in risk of preterm birth in Stockholm.

Odor and noise intolerance in persons with self-reported electromagnetic hypersensitivity

Lack of confirmation of symptoms attributed to electromagnetic fields (EMF) and triggered by EMF exposure has highlighted the role of individual factors. Prior observations indicate intolerance to other types of environmental exposures among persons with electromagnetic hypersensitivity (EHS). This study assessed differences in odor and noise intolerance between persons with EHS and healthy controls by use of subscales and global measures of the Chemical Sensitivity Scale (CSS) and the Noise Sensitivity Scale (NSS). The EHS group scored significantly higher than the controls on all CSS and NSS scales. Correlation coefficients between CSS and NSS scores ranged from 0.60 to 0.65 across measures. The findings suggest an association between EHS and odor and noise intolerance, encouraging further investigation of individual factors for understanding EMF-related symptoms.

Performance of multi-city land use regression models for nitrogen dioxide and fine particles

BACKGROUND

Land use regression (LUR) models have been developed mostly to explain intraurban variations in air pollution based on often small local monitoring campaigns. Transferability of LUR models from city to city has been investigated, but little is known about the performance of models based on large numbers of monitoring sites covering a large area.

OBJECTIVES

We aimed to develop European and regional LUR models and to examine their transferability to areas not used for model development.

METHODS

We evaluated LUR models for nitrogen dioxide (NO2) and particulate matter (PM; PM2.5, PM2.5 absorbance) by combining standardized measurement data from 17 (PM) and 23 (NO2) ESCAPE (European Study of Cohorts for Air Pollution Effects) study areas across 14 European countries for PM and NO2. Models were evaluated with cross-validation (CV) and hold-out validation (HV). We investigated the transferability of the models by successively excluding each study area from model building.

RESULTS

The European model explained 56% of the concentration variability across all sites for NO2, 86% for PM2.5, and 70% for PM2.5 absorbance. The HV R2s were only slightly lower than the model R2 (NO2, 54%; PM2.5, 80%; PM2.5 absorbance, 70%). The European NO2, PM2.5, and PM2.5 absorbance models explained a median of 59%, 48%, and 70% of within-area variability in individual areas. The transferred models predicted a modest-to-large fraction of variability in areas that were excluded from model building (median R2: NO2, 59%; PM2.5, 42%; PM2.5 absorbance, 67%).

CONCLUSIONS

Using a large data set from 23 European study areas, we were able to develop LUR models for NO2 and PM metrics that predicted measurements made at independent sites and areas reasonably well. This finding is useful for assessing exposure in health studies conducted in areas where no measurements were conducted.

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.

Air pollution exposure in early pregnancy and adverse pregnancy outcomes: a register-based cohort study

OBJECTIVES

Our aim was to study the possible associations between exposure to elevated levels of air pollution, ozone (O(3)) and vehicle exhaust (NO(x)), during early gestation, and adverse pregnancy outcomes such as pre-eclampsia, preterm birth and small for gestational age.

DESIGN

Prospective register-based cohort study.

SETTING

The Swedish Medical Birth Register includes data on all deliveries during 1998 to 2006 in Greater Stockholm, Sweden. The national Patient Register and the Prescribed Drug Register were used to collect information on maternal asthma.

PARTICIPANTS

All singleton pregnancies, conceived at the earliest in August 1997 and at the latest in February 2006, were included, n=120 755.

OUTCOME MEASURES

We studied preterm birth, small for gestational age and pre-eclampsia.

RESULTS

4.4% of pregnancies resulted in a preterm birth. The prevalence of pre-eclampsia was 2.7%. We observed an association between first trimester O(3) and preterm birth (OR 1.04, 95% CI 1.01 to 1.08) as well as an association with pre-eclampsia (OR 1.04, 95% CI 1.01 to 1.08), per 10 µg/m(3) increase in O(3). We observed no association between first trimester NO(x) and adverse pregnancy outcomes. No associations were observed between any of the air pollutants and small for gestational age.

CONCLUSIONS

Increased levels of O(3) during the first trimester increased the risk of pre-eclampsia and preterm birth. Air pollutants did not exhibit any effects on fetal growth restriction. We estimated 1 in every 20 cases of pre-eclampsia to be associated with O(3) exposure.

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.

Células-tronco mononucleares autólogas e proteína óssea morfogenética na cicatrização de defeitos tibiais experimentalmente induzidos em cães

Avaliou-se a utilização de células-tronco mononucleares (CTM) na cicatrização de defeito ósseo experimental como alternativa aos métodos convencionais, analisando-se o tempo de evolução cicatricial e a presença dessas células no tecido neoformado. Foram utilizados 18 cães, separados em três grupos (G) de seis, e de cada animal foram colhidas células da medula óssea (MO), contadas e analisadas para morfometria, por meio da contagem manual e mielograma. Um defeito ósseo tibial foi então criado cirurgicamente, e a lesão tratada com esponja de gelatina embebida em solução fisiológica (G1), esponja de gelatina embebida com aspirado de MO processado (G2) e esponja de gelatina embebida com aspirado de MO processado e proteína óssea morfogenética (rhBMP-2) (G3). A cicatrização foi então avaliada por estudos radiográficos, e a presença de CTM foi identificada por meio de marcadores nanocristais Qtracker, em microscopia com luz fluorescente, uma semana após a intervenção cirúrgica. Entre as células identificadas pelo marcador, foram encontradas células da linhagem óssea. As avaliações radiográficas demonstram crescimento ósseo acelerado nos animais de G2 e G3. Houve diferenças significativas entre o G1 e G3 em todos os tempos estudados, e entre G1 e G2 nos tempos de 30 e 45 dias. A utilização de CTM adultas suplementadas ou não com rhBMP-2 é alternativa favorável ao crescimento ósseo em defeitos experimentais agudos de tíbia de cães.

Combination therapy with interferon-beta and glatiramer acetate in multiple sclerosis

OBJECTIVES

To compare the effects of mono-therapy with interferon-beta (IFN-beta) or glatiramer acetate (GA) with IFN-beta + GA combination therapy for persons with multiple sclerosis (MS).

MATERIALS & METHODS

In the context of a longitudinal observational study at the MS Centre, Karolinska University Hospital, Huddinge, 83 persons with MS receiving mono-therapy at baseline were studied. Because of MS worsening 21 switched to IFN-beta + GA combination therapy for 16-24 months, and 62 remained on the same mono-therapy for 24 months. Multiple Sclerosis Functional Composite, cognitive function, depressed mood, relapse occurrence and perceived physical and psychological impact were assessed. Linear mixed-effects models and generalized estimating equations were employed to evaluate changes in each outcome over time.

RESULTS

Patients on IFN-beta + GA therapy showed greater change in odds for high perceived psychological impact. No other significant differences between treatments were found.

CONCLUSIONS

The results underline the need for a randomized trial of IFN-beta + GA in MS.

Violence from young women involuntarily admitted for severe drug abuse

OBJECTIVE

To simultaneously evaluate actuarial and dynamic predictors of severe in-patient violence among women involuntarily admitted for severe drug abuse.

METHOD

All patients admitted to special facilities for involuntary treatment of absconding-prone, previously violent, drug abusing women in Sweden were assessed with the Staff Observation Aggression Scale, revised. Actuarial data on risk factors for violence were collected and considered in an extended Cox proportional hazards model with multiple events and daily assessments of the Broset Violence Checklist as time-dependent covariates.

RESULTS

Low-grade violence and being influenced by illicit drugs were the best predictors of severe violence within 24 h. Significant differences in risk for violence between different institutions were also found.

CONCLUSION

In-patient violence risk is rapidly varying over time with being influenced by illicit drugs and exhibiting low-grade violence being significant dynamic predictors. Differences in violence between patients could not be explained by patient characteristics.

Nurses' short-term prediction of violence in acute psychiatric intensive care

OBJECTIVE

To evaluate the short-term predictive capacity of the Brøset Violence Checklist (BVC) when used by nurses in a psychiatric intensive care unit.

METHOD

Seventy-three patients were assessed according to the BVC three times daily. Violent incidents were recorded with the Staff Observation Aggression Scale, revised version. An extended Cox proportional hazards model with multiple events and time-dependent covariates was estimated to evaluate how the highest BVC sum of the last 24 h and its separate items affect the risk for severe violence within the next 24 h.

RESULTS

With a BVC sum of one or more, hazard for severe violence was six times higher than if the sum was zero. Four of the six separate items significantly increased the risk for severe violence with hazard ratios between 3.0 and 6.3.

CONCLUSION

Risk for in-patient violence in a short-term perspective can to a high degree be predicted by nurses using the BVC.

Emphysematous cystitis: rapid resolution of symptoms with hyperbaric treatment: a case report

INTRODUCTION

Emphysematous cystitis is a rare disease that occurs most often in elderly diabetic patients characterized by gas formation in the bladder wall due to infection. The infecting organism is usually an aerobic bacterium, most commonly E. coli although anaerobic species have also been reported. We report the use of hyperbaric oxygen in a patient with emphysematous cystitis and air in the femoral vein in which the treatment rapidly resolved the symptoms and radiological abnormalities.

METHODS

A 65-year-old female presented to the Emergency Department with altered mental status, weakness, dark urine, dysuria and fever. She was febrile and lethargic. Abdominal exam showed suprapubic tenderness. Urinalysis was positive for white blood cells and bacteria. A CT scan of the abdomen demonstrated extensive air in the bladder wall with an air bubble in the femoral vein. Presumptive diagnosis was urinary tract infection, emphysematous cystitis, and sepsis. A question of air embolism was raised due to the intravascular gas. The patient was treated with hyperbaric oxygen (2.85 atm abs, 90 minutes) on two separate occasions in the first 12 hours. Within 24 hours, the patient's condition rapidly improved. Repeat CT scan 48 hours after admission showed near complete resolution of the emphysematous cystitis. The patient grew Klebsiella pneumonia from her urine.

CONCLUSIONS

Emphysematous cystitis is a rare condition caused by either aerobic or anaerobic bacteria and may be associated with both bladder wall and intravascular gas formation. Hyperbaric oxygen therapy has not been previously reported as a treatment modality. The rapid improvement in our patient may indicate a role for hyperbaric oxygen in addition to IV hydration and antibiotics in this disease.

A multisite survey of factors contributing to medically unnecessary ambulance transports

OBJECTIVES

To determine the social and demographic factors associated with medically unnecessary ambulance utilization, and to determine the willingness of patients to use alternate modes of transportation to the ED.

METHODS

A multisite prospective survey was conducted of all patients arriving by ambulance to 1 suburban and 4 urban EDs in New York State during a 1-week period.

RESULTS

For 626 patients surveyed, 71 (11.3%) transports were judged medically unnecessary by the receiving emergency physicians using preestablished guidelines. The patient's type of medical insurance and age were significant predictors of unnecessary ambulance transport (stepwise forward logistic regression analysis). Of the 71 patients whose ambulance transports were deemed medically unnecessary, 42 (59%) were Medicaid recipients and 53 (74%) were < 40 years of age. The most common reason for using ambulance transport was lack of an alternate mode of transportation (38.5%), although 82% would have been willing to use an alternate mode of transportation if it had been available. Of those who had medically unnecessary ambulance use, 30% indicated that they would not pay for the ambulance service if billed and 50% believed the cost of their ambulance transports was < $100. More than 85% of the patients whose ambulance transports were deemed medically unnecessary were unemployed; and nearly 85% reported a net annual income of < $20,000. While 33% had a primary care provider, only 22% had attempted to contact their doctors before requesting an ambulance.

CONCLUSIONS

Patient age < 40 years and Medicaid coverage were associated with medically unnecessary ambulance use. Those patients for whom ambulance use was considered medically unnecessary commonly had no alternate means of transportation. Providing alternate means of unscheduled transportation may reduce the incidence of unnecessary ambulance use.

Adrenal medullary implants in the dopamine-denervated rat striatum. II. Acute behavior as a function of graft amount and location and its modulation by neuroleptics

Rotational behavior was studied in rats with unilateral 6-hydroxydopamine-induced degeneration of the nigrostriatal dopamine system, following intrastriatal grafting of pieces of the adrenal medulla or nervus opticus. The rats were placed in rotometers immediately after the operation. No rotational response was seen in animals implanted with nervus opticus. Rats that received one whole adrenal medullary gland, divided into 4 pieces, showed a strong rotational response with a peak after 100 min and a duration of 400 min. Adrenal medulla-induced rotations were dose-dependent: when rats were grafted with 2, 4 or 8 pieces (where 4 pieces equals one whole adrenal medulla) into 2 sites, 2 pieces induced about half the amount of rotation as 4 pieces, while 8 pieces caused a higher total number of rotations with the 100 min peak approximately doubled compared with rats that had received 4 pieces. The coordinates for the implantation site were also important determinants of the rotational behavior: 4 implantation sites were tested and it was shown that the most central site in the caudate caused the highest total amount of rotations. The rotational behavior could be blocked in a dose-dependent manner by the dopamine-receptor antagonists haloperidol and cis-flupenthixol given immediately after grafting. It is concluded that implantation of chromaffin tissue from the adrenal medulla into the unilaterally 6-hydroxydopamine-denervated striatum causes highly reproducible acute rotational responses that vary with the amount and location of the implanted tissue and that can be blocked by neuroleptics. Thus the experiments permit screening of areas within neostriatum that produce different rotational responses to chromaffin implants.(ABSTRACT TRUNCATED AT 250 WORDS)