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The increasing amount of electricity generated from wind power leads to a stronger variability in electricity supply to the national electricity grids. This makes wind power forecasts a necessary component in the wind energy market. The forecasts are used to estimate the amount of energy that will be generated and prevent potential imbalances between production and consumption in electricity grids. Energy price in Finland is set every day at the Nordic energy trading stock Nordpool. Unaccounted shortage or surplus of power in the grid needs to be compensated. This may result in costs required to balance the grid.To account for the uncertainties in wind power calculations, a probabilistic wind power forecasting tool has been developed. It is based on the MetCoOp Ensemble Prediction System (MEPS), in which the HARMONIE Numerical Weather Prediction model is run with 2.5 km horizontal resolution and 65 vertical levels. The system is operational through joint efforts of a group of Nordic countries participating in the MetCoOp cooperation.The skills of wind power calculations, however, depend not only on the skills of the MEPS system, but also on the information on the wind farms. Detailed information on the locations of wind turbines (WT), their hub heights and technical specifications is important in adequate calculations of power production and power losses. Most essential WT’s parameters are so-called power and thrust coefficient (CT) curves. Power curve is necessary to convert wind speed to corresponding power output. CT curve is needed to calculate wind flow retardation by WT, also called wake effect, resulting in power losses downwind in a wind farm. Power and CT curves, as well as other WT technical parameters, are turbine-specific and typically provided by the manufacturer under commercial terms and conditions. In power calculations over a country with a multitude of wind farms, gathering such information may be challenging.Nowadays power curves of many WT models can be found in open sources, such as thewindpower.net and wind-turbine-models.com. However, they are still missing for some and especially new WT models. CT curves, on the other hand, are practically not available in open sources. A statistical solution was developed to approximate both power and CT curves using as input commonly available WT specifications. The uncertainty in power calculations associated with approximated power and CT curves was found to be smaller than that associated with the uncertainty in the predicted wind speed.Wind to power conversion is done for essentially all WTs installed in Finland, to produce an aggregated probabilistic wind power forecast. Wind variability is accounted by applying Gaussian smoothening to power (and CT) curves. Wake-related losses were calculated applying Katic-Jensen wake model, with missing CT obtained applying the above method.

With the increase of solar power use, the need for solar irradiance forecasts is also increasing. Solar power is a naturally fluctuating energy source, which makes solar irradiance forecasts necessary for e.g. grid integration and management. Both the use of solar energy and the need for forecasts are present also in the Nordic countries, where the sub-Arctic latitude brings its own challenges.Various methods exist for forecasting solar irradiance. Numerical Weather Prediction (NWP) models have been found superior for forecasting for the following days, while satellite-based models are found suitable for the first few hours of the forecast. The satellite-based model Solis-Heliosat has been found to perform well also in the high latitudes. The current operational NWP models in Finland, however, have not been yet extensively validated for this purpose.To determine the suitability of the operational NWP models for forecasting solar irradiance in the Nordic countries, we have comparatively validated the MetCoOp Ensemble Model (MEPS), and the MetCoOp Nowcasting Model (MNWC) against in situ irradiance measurements at several stations in Finland and Sweden. We have also included the Solis-Heliosat model in the study, to improve our understanding on the differences and the relative accuracy between the NWP and satellite-based models. As a benchmark, two persistence models are included. The comparison is made for one summer, including all model runs and all MEPS ensemble members, with both hourly and 15 minute output depending on the model.The results show all models to somewhat under predict irradiance. MEPS shows very good performance in the full length of the forecast, while Solis-Heliosat is better in the first 2-3 hours of the forecast. Solis-Heliosat has some difficulty with the forecasts starting in the morning, whereas MNWC slightly struggles in the afternoon.Overall we find the NWP models very suitable for forecasting solar irradiance in Finland and Sweden, particularly with the full forecast horizon of MEPS, and the 15-minute time step of MNWC. Nevertheless, Solis-Heliosat brings further value to the beginning of the forecast.Kallio‐Myers, V., Riihelä, A., Schoenach, D., Gregow, E., Carlund, T., & Lindfors, A. V. (2022). Comparison of irradiance forecasts from operational NWP model and satellite‐based estimates over Fennoscandia. Meteorological Applications, 29(2), e2051.

Rakentamisen mitoitussäät (RAMI) -hankkeen tavoitteena oli määrittää mitoitusolosuhteet ja käytännöt rakenteiden lämpö- ja kosteusteknisen toiminnan sekä huonetilojen kesäaikaisen lämpötilan ja jäähdytystehontarpeen suunnittelua varten. Hankkeen lähtötietoina toimivat aiemmassa RASMI-hankkeessa määritetyt tuntiaineistot, joita täydennettiin ilmakehästä alaspäin suuntautuvan pitkäaaltosäteilyn osalta. Rakenteiden rakennusfysikaalisen toiminnan tutkimusosiossa valitut uudet mitoitusvuodet Jokioinen 2011 (yleiskriittinen vuosi), Jokioinen 2017 ja Vantaa 2017 sekä näitä vastaavat tulevaisuuden ilmasto-olosuhteiden vuodet kattavat yhdessä kaikki homeen kasvun tarkastelut koko Suomen alueella. Näiden lisäksi erikseen nimettyjä paikkakuntakohtaisia mitoitusvuosia voidaan hyödyntää kosteuden määrän sekä julkisivujen pakkasrasituksen ja betoniterästen korroosion tarkasteluissa. Kuukausitasolla tehtäviä kosteuden kondensoitumisen laskelmia varten mitoitusvuosiksi valittiin paikkakuntakohtaiset vuodet 2009–2010 heinäkuusta kesäkuuhun. Lisäksi tuloksissa on esitetty talvi- ja kesäkautta kuvaavia ulkoilman mitoittavia lämpötila- ja kosteusolosuhteita stationääritilanteiden laskelmia varten. Kiviainespintaisten julkisivujen rasitusolosuhteiden tutkimusosion perusteella ulkoilman hiilidioksidipitoisuuden, lämpötilan ja sademäärien muuttuminen nopeuttaa betonin karbonatisoitumista ja aktiivisen korroosion vaihetta, mutta vaikuttaa vaihtelevasti julkisivujen pakkasrapautumiseen riippuen paikkakunnasta ja julkisivun ilmansuunnasta. Työosion tuloksia hyödynnettiin rakennusfysiikan mitoitusvuosien valinnassa. Rakennusten sisäolosuhteiden ja jäähdytystehontarpeen mitoitusolosuhteisiin keskittyneessä tutkimusosiossa valittiin Suomen neljää säävyöhykettä kuvaaville paikkakunnille (Vantaa (I), Jokioinen (II), Jyväskylä (III) ja Sodankylä (IV)) kutakin vuoden kuukautta kuvaavat jäähdytyksen mitoituspäivät sekä mitoittavat entalpian ja ulkolämpötilan arvot nykyisille ja tulevaisuuden ilmasto-oloille. Matalimmalla ja keskimääräisellä päästöskenaariolla (RCP2.6 ja RCP4.5) ilmastonmuutoksen vaikutus mitoitusolosuhteisiin oli suhteellisen vähäinen, mutta korkeimman päästöskenaarion (RCP8.5) tapauksessa ilmastonmuutoksella alkaa jo olla enemmän vaikutusta jäädytysjärjestelmien mitoitukseen vuoden 2050 jälkeen.

Weather and climate information tailored to support decision-making in the built-up environment is becoming increasingly important. Energy-efficiency and climate resilience of buildings constitute a key subject in climate change mitigation and adaptation. Increasing outdoor air temperatures influence the heating and cooling energy demand of buildings and may increase the overheating risk of indoor conditions. Besides, more frequent rainfall events at the expense of snowfall in winter may intensify mold growth and moisture condensation in structures and slow down the drying of structures. Therefore, because buildings are designed to last for several decades, the planning, construction and maintenance of buildings need to be prepared for the changing weather conditions.The National Building Code of Finland demands that new buildings have to pass the nearly zero-energy requirements for energy performance and conformity, and this needs to be verified by calculations which use so-called test reference year (TRY) hourly weather data as input. TRY data sets describe typical present-day weather conditions during twelve months that usually originate from different years. Following the related standard (ISO 15927-4:2005) with a few modifications, the TRY data files have been constructed for Finland twice: in 2012 and 2020. While the former (TRY2012) is officially still in use, the latter (TRY2020) was recently developed with the aid of a newer set of weather observations, covering the period 1989-2018 and containing the following variables at hourly resolution: temperature, relative humidity, wind speed and direction, global, diffuse and direct solar radiation, and precipitation.An important part of work was to assess what kinds of weather conditions the built environment should be prepared for, depending on the forthcoming greenhouse gas emissions. Therefore, the tridecadal (1989-2018) weather datasets were transformed to represent future climate by modifying the hourly values of the weather variables in accordance with multi-model mean projections derived from an ensemble of 28 CMIP5 climate models. The transformations were performed using delta-change methods tailored for the various climatic variables. The observed partition of the global radiation between direct and diffuse components was also utilized in the transformation algorithm.The new climate information supports the design of healthy, safe and energy-efficient buildings in the changing climate of Finland. The work was part of a chain of multi-year ongoing research activities funded by the Ministry of the Environment and Healthy Premises 2028 program set by Prime Ministers´s Office. The materials produced in the project can also be utilized in education and scientific research. Previously, based on future scenarios linked to TRY2012, the annual energy demand was simulated to decrease by 20-40 % for heating and increase by 40-80 % for cooling in Finland by 2100.

Solar energy production is growing at a very high rate. This growth is present also in Fennoscandia, where solar energy can answer to the renewable energy need during the long summer days. Solar energy is a naturally fluctuating energy source, one that requires the use of solar irradiance forecasts for optimal operation. In northern locations clouds cause the largest fluctuations of irradiance, which is why the forecasting of solar irradiance is often focused on forecasting the movement of clouds. At high latitudes there are also specific challenges due to the location, for instance estimating cloud location at the edge of the geostationary satellite instrument viewing area.Forecasting irradiance is possible using various methods. Methods using satellite imagery, for instance, are good at forecasting irradiance for a few hours forward, while Numerical Weather Prediction (NWP) methods are recognised as superior for forecasting the next day. Validations have been made for various methods and setups, at several different locations, and for example the satellite-imagery-based method Solis-Heliosat has been shown to work well also at high latitudes. Operational NWP models, however, are not often validated for this specific purpose.To understand the performance of operational local area NWP models in irradiance forecasting in Fennoscandia, we have compared and validated NWP irradiance forecasts at several measurement stations in Finland and Sweden. In the comparison, we have included the operational weather forecast model in the Nordic countries, the MetCoOp Ensemble Model (MEPS), as well as the MetCoOp Nowcasting Model (MNWC). Additionally, we have included the Solis-Heliosat method and a persistence method in the comparison.Initial results show MEPS to have a steady, small relative bias error during the forecast, particularly after the first hours. The relative Root Mean Square Error (rRMSE) is also steady with only a slight increase during the whole forecast. MNWC somewhat underpredicts irradiance in the beginning, but the errors improve throughout the forecast. Solis-Heliosat has good initial accuracy, but the quality deteriorates very fast, with MEPS and MNWC outperforming the method after a 1-3 hour lead time. The Persistence method, as expected, has a very good bias, but also a very fast increasing rRMSE with forecast lead time.The results show the NWP methods to be very suitable for forecasting irradiance. Differences in best performing lead times and varying run times between the methods increase our interest in using both NWP and satellite-based methods in forecasting irradiance, to get the most optimal accuracy for both short and long-term forecasting.

Sand and Dust Storms (SDS) are extreme meteorological phenomena associated with high amounts of atmospheric mineral dust. SDS are an essential element of the Earth’s natural biogeochemical cycles but are also partly caused by human factors including anthropogenic climate change and unsustainable land and water management; in turn, SDS contribute to climate change and air pollution. SDS have become a serious global concern in recent decades due to their significant impacts on the environment, health, agriculture, livelihoods, and the economy. The impacts are felt throughout the developed and developing world and their mitigation is aligned with several of the United Nations’ Sustainable Development Goals. There has been an ever-increasing need for accurate information and predictions on SDS—particularly over desert regions such as the Sahara and in the Middle East—to support early warning systems as well as preparedness and mitigation plans, in addition to growing interest from diverse stakeholders and policymakers in the solar energy, health, environment and aviation sectors. The ongoing ERA4CS ‘Dust Storms Assessment for the development of user-oriented Climate services in Northern Africa, the Middle East and Europe’ (DustClim) project is enhancing our knowledge of the ways SDS affect society by producing and delivering an advanced dust regional model reanalysis for N. Africa, the Middle East and Europe, based on the MONARCH chemical weather prediction system (Pérez et al. 2011; Di Tomaso et al. 2017) and satellite retrievals over dust source regions, and by developing dust-related services tailored to strategic planning, operations, and policy-making in the air quality, aviation, and solar energy sectors. In this contribution, we will present how the resulting dust reanalysis is used as the basis to understand the mid-to-long-term impacts and implications of operating (and regulating) in risky sand and dust environments, namely: (1) the mineral dust component of air quality and its health and regulatory implications; (2) aircraft and airport operations, maintenance and planning; (3) strategic investment and operations optimization in solar energy. We will present our development approach that integrates scientific, industrial and regulatory knowledge, addressing ‘objective threats’ in dialogue with industry partners and public stakeholders (Votsis et al. 2020). Finally, we present an overview of the developed portfolio of SDS climate services for the three aforementioned sectors.Acknowledgment The authors acknowledge DustClim project, part of ERA4CS, an ERA-NET initiated by JPI Climate, and funded by FORMAS (SE), DLR (DE), BMWFW (AT), IFD (DK), MINECO (ES), ANR (FR) with co-funding by the European Union (435690462); PRACE (eDUST, eFRAGMENT1, eFRAGMENT2); RES (AECT-2020-3-0013) for awarding access to MareNostrum at BSC and for technical support.ReferencesDi Tomaso, E. et al. (2017): Assimilation of MODIS Dark Target and Deep Blue observations in the dust aerosol component of NMMB-MONARCH version 1.0, Geosci. Model Dev., 10, 1107-1129, doi:10.5194/gmd-10-1107-2017.Pérez, C. et al. (2011): An online mineral dust aerosol model for meso to global scales: Model description, annual simulations and evaluation, Atmos. Chem. Phys., 11, 13001-13027, doi: 10.5194/acp-11-13001-2011.Votsis, A. et al. (2020): Operational risks of sand and dust storms in aviation and solar energy: the DustClim approach, FMI's Climate Bulletin: Research Letters 1/2020, doi: 10.35614/ISSN-2341-6408-IK-2020-02-RL.

Power curves for a substantial number of wind turbine generators (WTG) became available in a number of public sources during the recent years. They can be used to estimate the power production of a wind farm fleet with uncertainty determined by the accuracy and consistency of the power curve data. However, in order to estimate power losses inside a wind farm due to wind speed reduction caused by the wake effect, information on the thrust force, or widely used thrust coefficient (Ct), is required. Unlike power curves, Ct curves for the whole range of operating wind speeds of a WTG are still scarcely available in open sources. Typically, power and Ct curves are requested from a WTG manufacturer or wind farm owner under a non-disclosure agreement. However, in a research study or in calculations over a multitude of wind farms with a variety of wind turbine models, collecting this information from owners may be hardly possible. This study represents a simple method to define Ct curve statistically using power curve and general specifications of WTGs available in open sources. Preliminary results demonstrate reasonable correspondence between simulated and given data. The estimations are done in the context of aggregated wind power calculations based on reanalysis or forecast data, so that the uncertainty of wake wind speed caused by the uncertainty of predicted Ct is comparable, or do not exceed, the uncertainty of given wind speed. Although the method may not provide accurate fits at low wind speeds, it represents an essential alternative to using physical Computational Fluid Dynamics (CFD) models that are both more demanding to computer resources and require detailed information on the geometry of the rotor blades and physical properties of the rotor, which are even more unavailable in open sources than power curves.

Background: Health-related quality of life (HR-QoL) is impaired in patients with hereditary angioedema (HAE) but has not yet been satisfactorily described.Objective: To study HR-QoL in patients wit ...

Few studies have been published on children with hereditary angioedema (HAE), an autosomal dominant disease caused by mutations on chromosome 11. This study explored various aspects of the disease in the Swedish paediatric population.A retrospective questionnaire was sent to all 36 Swedish children known to have HAE, and a physician carried out follow-up telephone interviews.Most of the questionnaires were completed by the parents of 31 (86%) children with HAE, with or without their input, at a median age of nine years (range 1-17), and the physician also interviewed 29. HAE symptoms were experienced by 23 children, including abdominal attacks (96%), skin swelling (78%) and swelling in the mouth and/or upper airways (52%). Psychological stress was the most common trigger for abdominal attacks and trauma and sports triggered skin swelling. The majority (n = 19) had access to complement-1 esterase inhibitor concentrate at home. Current health and quality of life were generally rated as good, independent of whether the child had experienced HAE symptoms or not.Most children with HAE had experienced abdominal attacks and skin swelling, but their overall health and quality of life were generally perceived to be good.

Hereditary angioedema (HAE) is rare, disabling and sometimes life-threatening. The aim of this study is to describe its prevalence, symptomatology and treatment in Sweden. A total of 146 patients were identified; 110 adults and 36 children with HAE type I (n = 136) or II (n = 10), giving a minimum HAE prevalence of 1.54/100,000. All patients received a written questionnaire followed by a structured telephone interview. This report focuses on the 102 adults who responded. Females reported 19 attacks in the previous year vs. 9 for males (p < 0.01), and females reported 10 days of sick leave vs. 4 days for males (p < 0.05). For all treated acute attacks, plasma-derived Cl-inhibitor concentrate (pdClINH) (used in 27% of patients) had a good effect. For maintenance treatment, 43% used attenuated androgens and 8% used pdClINH, which reduced their attack rate by more than 50%. In conclusion, the minimum HAE prevalence in Sweden was 1.54/100,000. HAE affected females more severely. Attenuated androgens and pdClINH had a good effect on preventing attacks. Funding Agencies|Futurum the Academy for Healthcare; Jonkoping County Council; Linkoping University; Karolinska Institutet

Hereditary angioedema (HAE) due to C1 inhibitor deficiency is a rare disease characterized by attacks of edema, known to impact quality of life (QoL). This study investigates the burden of HAE in Swedish patients, both children and adults. We used a retrospective registry study of Swedish patients with HAE, captured by the Sweha-Reg census. Data were collected using a paper-based survey. Patients completed EuroQoL 5 Dimensions 5 Levels (EQ5D-5L) questionnaires for both the attack-free state (EQ5D today), and the last HAE attack (EQ5D attack). Questions related to patient's age and sex and other variables, such as attack location and severity, were included to better understand the burden of HAE. EQ5D-5L values were estimated for the two HAE disease states. Patient-reported sick leave was also analyzed. A total of 103 responses were analyzed from 139 surveys (74% response rate). One hundred one reported an EQ5D today score (mean, 0.825) and 78 reported an EQ5D attack score (mean, 0.512) with significant differences between the two states (p0.0001). This difference was observed for both mild (p0.05), moderate (p0.0001), and severe attacks (p0.0001). Attack frequency had a negative effect on EQ5D today. Patients with30 attacks a year had a significantly lower EQ5D today score than those with less frequent attacks. Of 74 participants, 33 (44.6%) had been absent from work or school during the latest attack and, of those with a severe attack, 81% had been absent. HAE has a significant impact on QoL both during and between attacks and on absenteeism during attacks.

This paper describes the PROMOTE UV Record, which aims to provide a global long-term record of the surface UV radiation. The algorithm developed takes as input cloud information from the International Satellite Cloud Climatology Project (ISCCP) and a recently developed multisensor assimilated record of the total ozone column. Aerosols and surface albedo are based on climatologies. Here, first validation results of the PROMOTE UV Record are presented through comparison against ground-based measurements of daily erythemal UV doses at eight European stations. The validation shows that the method is working reasonably, although there is a clear tendency toward overestimation. Typically, the median bias as compared to measurements is 3%-10% and 56%-68% of the daily doses are within plusmn20% from the ground-based reference. The prototype version of the PROMOTE UV Record included in this paper covers the period from July 2002 to June 2005. The time series will later be extended to start in 1983.

Immunotherapy has been shown to reduce allergen sensitivity to allergens such as cat and dust mite. The aim of this study was to investigate the effect of cat or dust mite immunotherapy on bronchial hyperreactivity and the need for inhaled corticosteroids in children with asthma, cat or dust mite allergy, and hay fever.Twenty-nine children, 7 to 16 years old, completed the 3-year study. They were randomly allocated to receive cat/dust mite or placebo and birch/timothy immunotherapy.Before immunotherapy was begun and then once each year, bronchial histamine challenges were performed. Bronchial allergen challenge with the perennial allergen was done before and after the 3-year study. Pharmacotherapy was given according to a standardized protocol.PC20 allergen increased significantly in both the active immunotherapy group (P.001) and in the placebo-pollen group (P.05). PC20 histamine increased continuously in the active immunotherapy group (P.05 and P =.002 after 1 and 3 years, respectively) and had also increased after 3 years in the placebo-pollen group (P.05). The difference between the 2 groups was significant for PC20 allergen (P =.001) but not for PC20 histamine. There was no significant change in the dose of inhaled budesonide needed for symptom control in either of the groups.Pollen immunotherapy combined with inhaled corticosteroids results in improvement of both cat/dust mite bronchial sensitivity and hyperresponsiveness to histamine. The combination of cat or dust mite, pollen immunotherapy, and inhaled budesonide enhances this improvement. Cat immunotherapy also induces cat allergen tolerance.

Estimation of the thermal resistance ( R) and (especially) the thermal capacity (C) of building components from in situ measurements involves the analy sis of dynamic (not steady-state) heat flow data. Such analyses require a suitable dynamic model of the system. Such models, and thus analyses, are most elegantly handled in the frequency domain. Such modeling shows that in realistic experimental situations the presence of the heat flux transducer can have a significant effect on the dynamics of the system, even if the R and C of the transducer are much smaller than those of the component. This is confirmed by analysis of a real data set. Inclusion of the transducer in our model of the system produces estimates which, especially for short and highly dynamic data series, are more accurate and robust than those pro duced using more traditional time domain techniques.

Three-component data as an aid to seismic event detection and association : A case study using data from the SIL (Iceland) network

Background: Exposure to furred pets in early life has been considered to increase the risk of allergic sensitization and consequent development of asthma later in children. However, recently, it has been suggested that early exposure to pets prevents sensitization. The aim of this study was to evaluate the importance of early exposure to pets and other environmental risk factors in asthmatic children. Methods: This is a follow-up study after 2 years of a previously investigated group of 193 asthmatic children, aged 1–4 years. The study was completed by 181 children, who were clinically examined; serum IgE antibodies were also measured and a questionnaire was answered. Results: Children with reported exposure to cats during the first 2 years of life were more likely to have developed sensitization to cat by 4 years of age than unexposed children. High levels of cat allergen (Fel d 1≥8 µg/g dust) were associated with an increased risk of sensitization to cat and, in combination with tobacco smoke, also with the development of more severe asthma. Conclusions: In young asthmatic children, early exposure to cat and tobacco smoke increased the risk of allergic sensitization and further development of more severe asthma later in childhood.

The problem of the identification of a broad-band transient seismic signal crossing a seismic array is formulated in terms of complex demodulate covariances and the associated phase lags. Algorithms of this type provide a flexible, robust and very computationally efficient framework where we can allow for some of the complexities of the real world not easily handled by some other methods. e.g. nonlinear (curved) wavefronts, non-gaussian noise, outliers, and signal and noise correlation distance.

Quality of life and productivity loss in patients with hereditary angioedema (hae) in sweden; results from a retrospective patient registry survey implemented by sweha-reg (a population based census of hae in sweden)

The production of interleukin 2 (IL 2), IL 4 and interferon-gamma (IFN-gamma) by in vitro activated unselected human blood mononuclear cells was studied at a single-cell level. Individual lymphokine-synthesizing cells were identified by intracellular immunofluorescent staining using cytokine-specific monoclonal or polyclonal antibodies. Cultures from adult blood donors revealed a biphasic kinetic production pattern for IL 2 and IFN-gamma with peaks occurring 4-6 and 24-30 h after initiation of the cultures. Approximately 20%-40% of the lymphocytes produced IL 2 and IFN-gamma. In contrast, only 1%-3% of the lymphocytes synthesized IL 4 with maximal frequency after 6 h of culture. CD4+ as well as CD8+ T cells contributed to the synthesis of all three lymphokines studied. CD4+CD45R- T cells were the major producers of IL 2 and IL 4, while CD8+CD45R- T cells were the most common phenotype of IFN-gamma-synthesizing cells. By performing two-color immunofluorescence studies we observed that among IL 4-producing cells every second one made simultaneously IL 2 and every fourth one made IFN-gamma. Mononuclear cells from umbilical cord blood could be stimulated to make IL 2 to the same extent as cells from adult blood donors. No IL 4 production and a strikingly reduced frequency of IFN-gamma producers were noted in cell cultures from neonates. IL 2, IL 4 and IFN-gamma accumulated in the Golgi system, which resulted in a characteristic morphology of the staining, eliminating problems with evaluation of background signals.

Background: The increasing prevalence of asthma and allergy in many countries demands evaluation of potential risk factors to improve the possibility of prevention. Objective: We studied the association between exposure to cat and dog allergen and allergic sensitization in young children with asthma and interactions with potential environmental risk factors. Methods: One hundred eighty-nine young children with asthma were evaluated. IgE antibodies to cat and dog were analyzed. Questionnaires were filled in focusing on exposure to cats and dogs, environmental tobacco smoke (ETS), and signs of home dampness as indicated by window pane condensation (WPC) during the first years of life. House dust was analyzed for content of cat (Fel d 1) and dog (Can f 1) allergen. Results: There was a strong association between the degree of reported exposure to cat and dog and the concentration of the respective allergens in floor dust. A dose-response relationship was found between cat exposure, measured as either reported degree of cat exposure or cat allergen levels in dust, and sensitization both to cat and dog. No such relationship was found between exposure and sensitization to dog. WPC increased the risk for sensitization to cat (odds ratio=2.6, 95% confidence interval 1.2-5.8), whereas ETS strongly tended to do so both to cat and dog. Interaction was found between exposure to ETS, WPC, and high levels of cat allergen (>8 μg/g dust). The presence of all 3 risk factors revealed a multiplicative interaction with a high risk of sensitization to cat (odds ratio=42.0, 95% confidence interval 3.7-472.8). Conclusions: Keeping cats indoors may be a health hazard for infants and young children at risk for development of asthma, particularly when they live in a damp house and their parents smoke. (J Allergy Clin Immunol 1999;104:755-62.)