Esmeralda Krop

In-Traffic Air Pollution Exposure and CC16, Blood Coagulation, and Inflammation Markers in Healthy Adults

Background: Exposure to traffic-related air pollution is a risk factor for cardiovascular events, probably involving mechanisms of inflammation and coagulation. Little is known about effects of the short exposures encountered while participating in traffic. Objectives: The objective of the study was to examine effects of exposure of commuters to air pollution on cardiovascular biomarkers. Methods: Thirty-four healthy adult volunteers commuted for 2 hr by bus, car, or bicycle during the morning rush hour. During the commute, exposure to particle number, particulate matter (PM) ≤ 2.5 µm in aerodynamic diameter (PM2.5), PM ≤ 10 µm in diameter (PM10), and soot was measured. We estimated inhaled doses based on heart rate monitoring. Shortly before exposure and 6 hr after exposure, blood samples were taken and analyzed for CC16 (Clara cell protein 16), blood cell count, coagulation markers, and inflammation markers. Between June 2007 and June 2008, 352 pre- and postexposure blood samples were collected on 47 test days. We used mixed models to analyze the associations between exposure and changes in health parameters. Results: We observed no consistent associations between the air pollution exposures and doses and the various biomarkers that we investigated. Conclusions: Air pollution exposure during commuting was not consistently associated with acute changes in inflammation markers, blood cell counts, or blood coagulation markers.

Plasma Cytokines and Future Risk of Non-Hodgkin Lymphoma (NHL): A Case-Control Study Nested in the Italian European Prospective Investigation into Cancer and Nutrition

Background: Recently, biological markers related to the immune system such as cytokines have been studied to further understand the etiology of non-Hodgkin Lymphoma (NHL). However, to date, there are no studies that have studied cytokine levels prospectively in relation to NHL risk in the general population. Methods: Using bead-based immunoassays, plasma levels of 11 cytokines, 4 chemokines, and 1 adhesion molecules were measured in prediagnostic blood samples of 86 NHL cases and 86 matched controls (average time between blood collection and diagnosis, 4.5 y). Conditional logistic regression adjusted for body mass index and alcohol consumption was used to analyze the association between individual plasma cytokine levels and the risk of developing NHL. Results: In multivariate models, excluding cases diagnosed within 2 years after inclusion, we observed a significant association for interleukin 2 (IL2; P trend = 0.004), interferon (IFN)-γ (P trend = 0.05), and intercellular adhesion molecule (ICAM) (P trend = 0.04). Subanalyses of B-cell NHL patients showed a significant association with IL2 (P trend = 0.003), tumor necrosis factor-α (TNF-α; P trend = 0.03), and ICAM (P trend = 0.04) and a borderline association with IL5 (P trend = 0.07) and IFN-γ (P trend = 0.08). Conclusions: The results of this study suggest, in a prospective setting, a possible association between plasma levels of IL2, ICAM, IFN-γ, and TNF-α with NHL risk and provide some evidence that risk of NHL might be related to a downregulation of T helper 1 cytokines. Impact: Identification of subtle changes in immune response regulation quantified by plasma cytokine levels possibly provides new insights in the etiology of NHL. Cancer Epidemiol Biomarkers Prev; 19(6); 1577–84. ©2010 AACR.

Mouse allergen-specific immunoglobulin G and immunoglobulin G4 and allergic symptoms in immunoglobulin E-sensitized laboratory animal workers.

Background High levels of allergen‐specific IgG have been associated with clinical efficacy in immunotherapy studies, but whether this antibody isotype is associated with clinical tolerance in the setting of environmental exposure remains unclear.

Spreading of occupational allergens: laboratory animal allergens on hair-covering caps and in mattress dust of laboratory animal workers.

Background: Family members of laboratory animal workers are at risk of developing allergy to laboratory animals. Little is known about the spreading of laboratory animal allergens outside the animal facilities. Objective: To assess the presence of laboratory animal allergens in dust collected from mattresses of laboratory animal workers and unexposed controls. Methods: Mouse and rat urinary proteins were measured in samples of mattress dust collected by laboratory animal workers and unexposed controls. In addition, rat and mouse allergens were determined in extracts of hair-covering caps, used during laboratory animal work, to estimate spreading of allergen through dust captured on hair. Allergen concentrations on hair caps were compared with exposure measured by personal airborne dust sampling. Results: Levels of rat urinary allergens (RUA) and mouse urinary allergens (MUA) and mouse urinary protein (MUP) 8, a specific pheromone-binding mouse allergen, were significantly higher in mattress samples of laboratory animal workers than in those of controls. Hair-covering caps used in animal facilities harboured large amounts of RUA and MUA, which correlated significantly with exposure measured by the personal sampling technique in the animal facility. Conclusions: Occupational laboratory animal allergens are detectable in mattress dust of laboratory animal workers. Transfer of allergens via uncovered hair of animal workers is likely contributing to this phenomenon. This study stresses the importance of using hair caps to prevent spreading of occupational allergens.

Microbial secondary metabolites in school buildings inspected for moisture damage in Finland, The Netherlands and Spain

Secondary metabolites produced by fungi and bacteria are among the potential agents that contribute to adverse health effects observed in occupants of buildings affected by moisture damage, dampness and associated microbial growth. However, few attempts have been made to assess the occurrence of these compounds in relation to moisture damage and dampness in buildings. This study conducted in the context of the HITEA project (Health Effects of Indoor Pollutants: Integrating microbial, toxicological and epidemiological approaches) aimed at providing systematic information on the prevalence of microbial secondary metabolites in a large number of school buildings in three European countries, considering both buildings with and without moisture damage and/or dampness observations. In order to address the multitude and diversity of secondary metabolites a large number of more than 180 analytes was targeted in settled dust and surface swab samples using liquid chromatography/mass spectrometry (LC/MS) based methodology. While 42%, 58% and 44% of all samples collected in Spanish, Dutch and Finnish schools, respectively, were positive for at least one of the metabolites analyzed, frequency of detection for the individual microbial secondary metabolites - with the exceptions of emodin, certain enniatins and physcion - was low, typically in the range of and below 10% of positive samples. In total, 30 different fungal and bacterial secondary metabolites were found in the samples. Some differences in the metabolite profiles were observed between countries and between index and reference school buildings. A major finding in this study was that settled dust derived from moisture damaged, damp schools contained larger numbers of microbial secondary metabolites at higher levels compared to respective dust samples from schools not affected by moisture damage and dampness. This observation was true for schools in each of the three countries, but became statistically significant only when combining schools from all countries and thus increasing the sample number in the statistical analyses.

Occurrence of moisture problems in schools in three countries from different climatic regions of Europe based on questionnaires and building inspections - the HITEA study.

UNLABELLED The aim of this study was to assess occurrence of dampness and mold in school buildings in three European countries (the Netherlands, Spain, and Finland), representing different climatic regions. An assessment was performed utilizing both questionnaires and on-site building investigations, and the agreement between these two methods was evaluated for validation purposes. On the basis of questionnaire data from a representative sample of schools, different types of moisture problems were reported in 24-47% of all school buildings at the time of the study. Most commonly reported was dampness in the Netherlands, moisture/water damage in Spain, and mold odor in Finland. Subsequently, 20-24 schools per country were selected for on-site inspections by trained staff. The overall agreement between the questionnaire and inspection data was good (kappa-value 0.62), however, with large differences (0.39-0.91) between countries. Extrapolating from the inspection data, the minimum estimates for prevalence of moisture problems in school buildings are 20% in the Netherlands, 41% in Spain, and 24% in Finland. In conclusion, moisture problems (such as moisture damage, dampness, and mold) are relatively common in schools. The occurrence and severity may vary across geographical areas, which can be partly explained by building characteristics. PRACTICAL IMPLICATIONS On the basis of this study, the prevalence of verified moisture problems in school buildings was highest in Spain, but lower and similar in Finland and the Netherlands. Questionnaire-based surveys can be used to assess moisture problems in school buildings, but because of large variation in agreement with inspection data, the questionnaire needs to be validated by on-site inspections in a subsample of the surveyed buildings.

Allergen and endotoxin exposure in a companion animal hospital.

Background Exposure to allergens, both in general and occupational environments, is known to result in sensitisation and exacerbation of allergic diseases, while endotoxin exposure might protect against allergic diseases. This may be important for veterinarians and co-workers. However, exposure levels are mostly unknown. Objective We investigated the allergen and endotoxin exposure levels of veterinary medicine students and workers in a companion animal hospital. Methods Airborne and surface dust was collected using various sampling methods at different locations. Allergen levels in extracts were measured with sandwich ELISAs and/or the multiplex array for indoor allergens (MARIA). Endotoxin was determined by limulus amebocyte lysate (LAL) assay. Results Fel d 1 (Felis domesticus), Can f 1 (Canus familiaris) and endotoxin were detected in all except stationary samples. The geometric mean (GM) level of personal inhalable dust samples for Fel d 1 was 0.3 ng/m3 (range: below lower limit of detection (<LOD) to 9.4), for Can f 1 3.6 ng/m3 (<LOD to 73.3) and for endotoxin 4.4 EU/m3 (<LOD to 75). Exposure levels differed significantly between job titles, with highest allergen exposure for student assistants in the intensive care unit (Fel d 1, GM 1.5 ng/m3; Can f 1, GM 18.5 ng/m3), and highest endotoxin exposure for students (GM 10.1 EU/m3). Exposure levels in dust captured by diverse sampling methods correlated with each other (p<0.05). Conclusion Allergen exposure likely occurs during veterinary practice, with relatively low endotoxin levels. Future research should investigate dose–response relationship between airborne allergen exposure and health effects.

Stability and reproducibility of simultaneously detected plasma and serum cytokine levels in asymptomatic subjects

Blood levels of cyto- and chemokines might reflect immune deregulations which might be related to lymphomagenesis. Potential utility of stored blood samples of a prospective cohort was evaluated by the effect of different blood sample types and freeze-thaw cycles on analyte levels. Bead-based immunoassays were performed on two fresh samples (serum, citrate and heparin plasma) of 10 asymptomatic adults collected 14 days apart and on aliquots of the first samples which were put through one to three freeze-thaw cycles to measure 11 cytokines, four chemokines and two adhesion molecules. Median coefficients of variation (CVs) of the measured analytes were 20%, 24% and 32% in serum, citrate and heparin plasma, respectively. Strong correlations (rank correlation coefficient 0.74–0.98) were observed between sample types, although small differences in analyte levels were observed for most analytes. Freeze-thaw cycles did not markedly change analyte levels. Our study supports the use of this assay among asymptomatic subjects in epidemiological studies.

Monitoring of occupational and environmental aeroallergens - EAACI Position Paper Concerted action of the EAACI IG Occupational Allergy and Aerobiology & Air Pollution

Exposure to high molecular weight sensitizers of biological origin is an important risk factor for the development of asthma and rhinitis. Most of the causal allergens have been defined based on their reactivity with IgE antibodies, and in many cases, the molecular structure and function of the allergens have been established. Significant information on allergen levels that cause sensitization and allergic symptoms for several major environmental and occupational allergens has been reported. Monitoring of high molecular weight allergens and allergen carrier particles is an important part of the management of allergic respiratory diseases and requires standardized allergen assessment methods for occupational and environmental (indoor and outdoor) allergen exposure. The aim of this EAACI task force was to review the essential points for monitoring environmental and occupational allergen exposure including sampling strategies and methods, processing of dust samples, allergen analysis, and quantification. The paper includes a summary of different methods for sampling and allergen quantification, as well as their pros and cons for various exposure settings. Recommendations are being made for different exposure scenarios.

Dampness and mould in schools and respiratory symptoms in children: the HITEA study

Background The adverse respiratory health effects of dampness and mould in the home have been extensively reported, but few studies have evaluated the health effects of such exposures in schools. Objectives To assess the associations between dampness and mould in school buildings and respiratory symptoms among 6–12-year-old pupils in three European countries with different climates. Methods Based on information from self-reports and observations, we selected 29 primary schools with and 27 without moisture damage in Spain, the Netherlands and Finland. Information on respiratory symptoms and potential determinants was obtained using a parent-administered questionnaire among 6–12-year-old pupils. Country-specific associations between moisture damage and respiratory symptoms were evaluated using multivariable multilevel mixed effects logistic regression analysis. Results Data from 9271 children were obtained. Nocturnal dry cough was consistently associated with moisture damage at school in each of the three countries: OR 1.15; 95% CI 1.00 to 1.30 with p for heterogeneity 0.54. Finnish children attending a moisture damaged school more often had wheeze (OR 1.36; CI 1.04 to 1.78), nasal symptoms (OR 1.34; CI 1.05 to 1.71) and respiratory-related school absence (OR 1.50; CI 1.10 to 2.03). No associations with these symptoms were found in the Netherlands or Spain (p for heterogeneity <0.05). Conclusions Moisture damage in schools may have adverse respiratory health effects in pupils. Finnish school children seem to be at higher risk, possibly due to quantitative and/or qualitative differences in exposure.