Seasonal cycle of VOCs in apartments.

To assess the adverse health effects of volatile organic compounds (VOCs), epidemiological studies combine the health outcome of individuals with their concomitant VOC exposure. While the latter is representative of the studied period, health effects might also be the result of long-term exposure or emerge in consequence of a peak pollution throughout the year. To address these problems, additional information about the spatiotemporal distribution of VOCs is necessary. The present paper aims at elucidating the spatial and temporal variation of VOC concentrations in Leipzig, Germany. The analysis is based on 1499 indoor and 222 outdoor measurements taken in the period between 1994 and 2001. All data were collected in the frame of epidemiological studies (Diez et al., 1999; Fritz et al., 1998; Schulz et al., 1999). The analysis comprised concentrations of 30 VOCs belonging to the groups of alkanes, cycloalkanes, aromatics, volatile halogenated hydrocarbons, and terpenes. We found that the VOC load in indoor air is, on average, 10 times higher than outdoors. For the studied period there was a clear downward tendency for all VOCs in apartments in Leipzig, except for terpenes which show an upward trend in the period 1996-99. In indoor air we observe an annual cycle for the total VOC concentration as well as the sum concentrations of the above called groups. Highest concentrations occur during the winter months, approximately three times higher than the summer burden. We summarize this finding in a seasonal model, which is fitted to our measurements. Based on the model we develop a procedure for seasonal adjustment, which enables to roughly estimate the annual peak concentration utilizing one monthly observation.

The influence of maternal exposure to volatile organic compounds on the cytokine secretion profile of neonatal T cells.

Indoor VOC (volatile organic compound) exposure has been shown to be correlated with airway symptoms and allergic manifestations in children. An investigation was conducted within an ongoing birth cohort study (LISA: Lifestyle-Immune System-Allergy) of the association between maternal exposure to VOCs and immune status at birth, in particular the cytokine secretion profile of cord-blood T cells. In a randomly selected group of 85 neonates, cytokine-producing cord-blood T cells were analyzed using intracellular cytokine detection. VOC exposure was measured in children's dwellings by passive sampling, while parents were asked to complete questionnaires about possible sources of VOC exposure. Adjusted odds ratios (ORs) were calculated by logistic regression based on categorized quartiles. A positive association was found between elevated percentages of interleukin-4-producing (IL-4) type 2 T cells and exposure to naphthalene (OR = 2.9) and methylcyclopentane (OR = 3.3). Exposure to tetrachloroethylene was associated with reduced percentages of interferon-gamma-producing (IFN-gamma) type 1 T cells (OR = 2.9). In addition, smoking during pregnancy was correlated with a higher indoor air concentration of naphthalene (OR = 3.8), new carpets in infants' bedrooms with elevated methylcyclopentane concentrations (OR = 4.1), and home renovation with a higher trichloroethylene burden (OR = 4.9). Our data suggest that maternal exposure to VOC may have an influence on the immune status of the newborn child.

Assessment of mutagenicity and toxicity of different-size fractions of air particulates from La Plata, Argentina, and Leipzig, Germany.

Airborne particulates, especially fine particles and bound chemical compounds, are a potential mediator of adverse health effects. In this study an analysis was done of the concentration and size distribution of air particulate matter, the content of bound polycyclic aromatic hydrocarbons (PAHs), and the biological effects of organic extracts from different fractions of dust that had been influenced by urban and industrial emissions from the regions of La Plata, Argentina, and Leipzig, Germany, along with samples from control areas. Air particulate matter was sampled in summer and winter in each region using a high-volume sampler with a six-stage cascade impactor, classifying dust in six size fractions from 10-microm particles to those less than 0.49 microm in size. Organic extracts of dust were tested for mutagenicity (Ames test, Salmonella typhimurium TA98 strain, S9+) and cytotoxicity (Tetrahymena pyriformis test system, growth rate, cell respiration). The content of PAHs was analyzed by high-performance liquid chromatography (HPLC) with diode array and fluorescence detection. Mutagenic and cytotoxic effects were found to be associated with very fine (<0.49 microm) and fine (<1.5 microm) particle-bound compounds, corresponding to a higher content of PAHs. The mutagenic potency (revertants/m(3)) associated with particles less than 0.49 microm from urban areas of La Plata was about 1 order of magnitude higher than in particles in the range of 3.0 to 0.49 microm. Fine fractions from sites with an industrial burden were also found to exhibit high mutagenic potency. A similar tendency was observed in cytotoxicity tests with T. pyriformis. This cell system proved to be very sensitive to toxicants in tested dust fractions. The observed biological effects were found to be correlated significantly with concentrations of total PAH, carcinogenic PAHs, and benzo[a]pyrene.

The [15N]methacetin liver function test characterizes multicomponent exposure of children in industrially polluted regions.

The [15N]methacetin urine test for assessing disturbances of the cytochrome P450-aided oxygenation of xenobiotics in the human liver has been approved in several environmental health studies. A recent longitudinal study of kindergarten children near chemical and mining companies undergoing fundamental restructuring showed high, seasonally fluctuating SO2 burden which was well correlated with alterations in the mean liver states of the children. At one point the correlation disappeared, together with indications of large amounts of chlorinated compounds overflowing locally at nighttime. This was finally proven by analyzing urine samples from the children for trichloroacetic acid (TCA). Chlorinated ethanes and ethenes-the precursors of TCA-seemed to dominate the air pollution and to affect the hepatic detoxification capacity. We concluded that the methacetin liver function test reflects multicomponent exposure, including acute monopolization by a dominant pollutant for a time.

Enhanced in vivo IgE production and T cell polarization toward the type 2 phenotype in association with indoor exposure to VOC: results of the LARS study.

The association between indoor exposure to volatile organic compounds (VOC), prevalence of allergic sensitization and cytokine secretion profile of peripheral T cells was studied in 3 year old children of the LARS study (Leipzig Allergy Risk Children Study) to investigate the role of VOC exposure as a risk factor for the development of atopic disease. Indoor VOC exposure was measured over a period of 4 weeks in infants' bedrooms using a passive sampling system. Specific IgE antibodies to food, indoor and outdoor allergens were measured by the Pharmacia CAP system and correlated to VOC exposure (n = 120). In addition, cytokine producing peripheral T cells (interleukin(IL)-4, interferon(IFN)-gamma) were measured in a subgroup of 28 children by means of intracellular cytokine staining. For the first time we were able to show that exposure to alkanes (C6, C9, C10) and aromatic compounds (toluene, o-xylene, m + p-xylene, 2-, 3- and 4-ethyl-toluene, chlorobenzene) may contribute to the risk of allergic sensitization to the food allergens milk and egg white (Odds ratios between 5.7 and 11.2). Moreover, significantly reduced numbers of CD3+/CD8+ peripheral T cells were found in children exposed to alkanes (C9-C13), naphthalene and chlorobenzene. Exposure to benzene, ethylbenzene and chlorobenzene was associated with higher percentages of IL-4 producing CD3+ T cells. Both an increase in IL-4 producing type 2 T cells and a reduction of IFN-gamma producing type 1 T cells may contribute to a type 2 skewed memory in response to allergens. Therefore, we suggest exposure to VOCs in association with allergic sensitization to be mediated by a T cell polarization toward the type 2 phenotype.

Effects of indoor painting and smoking on airway symptoms in atopy risk children in the first year of life results of the LARS-study. Leipzig Allergy High-Risk Children Study.

INTRODUCTION: The Leipzig Allergy High-Risk Children Study (LARS) is a prospective nested cohort control study about the influence of chemical indoor exposure in dwellings on the health outcome of atopy-risk children during the first years of life. DESIGN AND METHODS: 475 premature children and children with allergic risk factors have been selected out of the 1995/1996 birth cohort in the city of Leipzig. Twenty-five volatile organic compounds (VOC) were measured in the infant's bedrooms using passive sampling systems for 4 weeks after birth. The babies underwent a medical examination at the age of six weeks and 1 year. The parents answered a questionnaire. RESULTS: Correlations between VOC exposures and infections were calculated by multiple logistic regression. Selected VOC show a direct association to actually painted dwellings (OR = 2.4; 95% Cl 1.1-5.3). An increase of risk of pulmonary infections was observed in infants aged 6 weeks if restoration (painting OR 5.6; 95% Cl 1.3-24.0) or flooring connected with painting had occurred during the pregnancy period. Higher concentration of styrene (> 2.0 micrograms/m3, indicator for flooring) elevated the risk of pulmonary infections in six-week-old infants (OR = 2.1; 95% Cl 1.1-4.2). Environmental benzene > 5.6 micrograms/m3 increased the risk of airway infections in six-week-old babies (OR = 2.4; 95% Cl 1.28-4.48). Smoking in the dwelling (OR = 2.0; 95% Cl 1.1-3.5) as well as restoration (OR = 1.9; 95% Cl 1.1-3.5) are also risk factors of the development of wheezing in the one-year-old child. CONCLUSIONS: The data give indications in order to prevent allergies and chronic lung diseases in atopy risk children exposure to chemicals from indoor air should be minimised from birth on.

Mycotoxins in house dust - an underestimated problem?

People in developed countries spend up to 90% of their time indoors. This led to an increased awareness for problems regarding indoor environment in recent years. It is known that especially spores, mycelia and organic compounds released by the microbial colony e.g. mycotoxins and microbial volatile organic compounds (MVOCs) can be harmful to human health. The aim of a pilot program is to investigate mould-dependent health complaints in a burdened population of the city of Leipzig, Germany. Phase 1 of the investigation includes inspection of dwellings, determination of exposure and clinical examination of exposed persons. In phase 2 it is planned to analyse the influence of burdens with mould spores and their metabolites like mycotoxins on health complaints. House dust seems to be a representative sample medium for sedimented spores and mycelia which may contain mycotoxins. The analysis will be performed by LC-MS-MS after extraction of the crude dust samples by accelerated solvent extraction. The qualitative proof of mycotoxins in house dust was successful in a case study with a high burden.

Ozone-monitoring in Mendoza, Argentina: initial results.

A series of continuous ambient tropospheric ozone measurements were taken in Mendoza, Argentina, for a period of one year starting in November 1995. The data obtained were analyzed in terms of diurnal and annual variation. Indications were found of the strong impact of the mountain-valley circulation system, which ventilates and considerably cleans the air in Mendoza. The data are discussed in comparison with air pollution in the German city of Leipzig. In Mendoza, the high concentration of precursors and the strong solar radiation contribute to high levels of ozone. In fact, monitoring reveals considerably lower concentrations than in Leipzig, owing to the diluting effect of local meteorology. The low-level jet is mainly active during the summer. It lowers the peak mid-day ozone concentration and produces a temporary concentration increase at night. The Environmental Protection Agency standard of a maximum one-hour mean concentration of 0.250 mg ozone/m3 (125 ppb) is never reached, and the World Health Organization standard of 0.113 mg ozone/m3 (56.5 ppb) is only rarely exceeded during winter.