Elemental carbon and respirable particulate matter in the indoor air of apartments and nursery schools and ambient air in Berlin (Germany).

UNLABELLED: This study was performed to examine exposure to typical carcinogenic traffic air pollutants in the city center of an urban area. In all, 123 apartments and 74 nursery schools were analyzed with and without tobacco smoke interference and the households in two measuring periods. Simultaneously, the air outside 61 apartment windows as well as the average daily traffic volume were measured. Elemental carbon (EC), the marker for particulate diesel exhaust and respirable particulate matter (RPM) were determined. The thermographic EC analysis was conducted with and without prior solvent extraction of the soluble carbon fraction. Comparison of these two thermographic EC measurements clearly showed that method-related differences in the results, especially for indoor measurements, when high background loads of organic material were present (e.g. tobacco smoke), existed. Solvent extraction prior to EC determination was therefore appropriate. For the first winter measuring period, the EC concentration levels without solvent extraction in the indoor air were about 50% higher than those measured in the spring/summer period. In the second measuring period (i.e. spring/summer), the median EC concentrations after solvent extraction were 1.9 microg/m3 for smokers' apartments and 2.1 microg/m3 for non-smokers' apartments, with RPM concentrations of 57 and 27 microg/m3, respectively. Nursery schools showed high concentrations with median values of 53 microg/m3 for RPM and 2.9 microg/m3 for EC after solvent extraction. A significant correlation between the fine dust and EC concentrations (after solvent extraction) in the indoor and ambient air was determined. Outdoor EC values were also correlated with the average daily traffic volume. The EC ratios between indoor and ambient concentration showed a median of 0.8 (range: 0.3-4.2) in non-smoker households and 0.9 (range: 0.4-1.5) in smoker apartments. Furthermore, the EC/RPM ratio in indoor and ambient air was 0.01-0.15 (median 0.06) and 0.04-0.37 (median 0.09), respectively. PRACTICAL IMPLICATIONS: In the absence of indoor sources a significant correlation with regard to respirable particulate matter (RPM) and elemental carbon concentrations between the indoor and ambient air of apartments was observed. The high degree of certainty resulting from this correlation underscores the importance of ambient air concentrations for indoor air quality. In nursery schools we found higher concentrations of RPM. An explanation of these results could be the high number of occupants in the room, their activity and the cleaning intensity.

Polycyclic aromatic hydrocarbons inside and outside of apartments in an urban area.

In the context of environmental monitoring in Berlin polycyclic aromatic hydrocarbon (PAH) concentrations in air and household dust were measured inside 123 residences (and simultaneously in a sub group in the air outside the windows). The aim of this study was to determine exposure to PAHs in the environment influencing by several factors, for instance, motor vehicle traffic in a populous urban area. Indoor air samplings were carried out in two periods (winter and spring/summer) in smokers and non-smokers apartments. Benzo(a)pyrene (BaP) median values were 0.65 ng m(-3) (winter) and 0.27 ng m(-3) (spring/summer) in smokers' apartments and 0.25 ng m(-3) (winter) and 0.09 ng m(-3) (spring/summer) in the apartments of non-smokers. The median BaP content in ambient air was 0.10 ng m(-3) (maximum: 1.1 ng/m(-3)) with an indoor-outdoor mean concentration ratio of 0.9 in non-smoker households and 5.4 in smoker apartments. In household dust we obtained median values of 0.3 mg kg(-1) (range: 0.1-1.4 mg kg(-1)). We found a significant relation between indoor and outdoor values. Approximately 75% of the variance of indoor air values was caused by the corresponding BaP concentrations in the air outside the apartment windows. Otherwise a significant correlation between indoor air and household dust values cannot be found. Therefore, according to our results, it is suggested that the indoor PAH concentration in non-smoker apartments could be attributed mainly to vehicular emissions.

Occurrence of phthalates and musk fragrances in indoor air and dust from apartments and kindergartens in Berlin (Germany).

UNLABELLED: In this study, the occurrence of persistent environmental contaminants room air samples from 59 apartments and 74 kindergartens in Berlin were tested in 2000 and 2001 for the presence of phthalates and musk fragrances (polycyclic musks in particular). These substances were also measured in household dust from 30 apartments. The aim of the study was to measure exposure levels in typical central borough apartments, kindergartens and estimate their effects on health. Of phthalates, dibutyl phthalate had the highest concentrations in room air, with median values of 1083 ng/m(3) in apartments and 1188 ng/m(3) in kindergartens. With around 80% of all values, the main phthalate in house dust was diethylhexyl phthalate, with median values of 703 mg/kg (range: 231-1763 mg/kg). No statistically significant correlation could be found between air and dust concentration. Musk compounds were detected in the indoor air of kindergartens with median values of 101 ng/m(3) [1,3,4,6,7,8-hexahydro-4,6,6,7,8,8- hexamethylcyclopenta-(g) 2-benzopyrane (HHCB)] and 44 ng/m(3) [7-acetyl-1,1,3,4,4,6-hexamethyl-tetraline (AHTN)] and maximum concentrations of up to 299 and 107 ng/m(3) respectively. In household dust HHCB and AHTN were detected in 63 and 83% of the samples with median values of 0.7 and 0.9 mg/kg (Maximum: 11.4 and 3.1 mg/kg) each. On comparing the above phthalate concentrations with presently acceptable tolerable daily intake values (TDI), we are talking about only a small average intake [di(2-ethylhexyl) phthalate and diethyl phthalate less than 1 and 8% of the TDI] by indoor air for children. The dominant intake path was the ingestion of foodstuffs. For certain subsets of the population, notably premature infants (through migration from soft polyvinyl chloride products), children and other patients undergoing medical treatment like dialysis, exchange transfusion, an important additional intake of phthalates must taken into account. PRACTICAL IMPLICATIONS: The phthalate and musk compounds load in a sample of apartments and kindergartens were low with a typical distribution pattern in air and household dust, but without a significant correlation between air and dust concentration. The largest source of general population exposure to phthalates is dietary. For certain subsets of the general population non-dietary ingestion (medical and occupational) is important.

Polycyclic aromatic hydrocarbons (PAH) and diesel engine emission (elemental carbon) inside a car and a subway train.

Significant concentrations of potentially harmful substances can be present in the interior of vehicles. The main sources of PAHs and elemental carbon (EC) inside a car are likely to be combustion emissions, especially from coal and traffic. The same sources can also be important for the interior of a subway train for which there are specific sources in the tunnel system, for example diesel engines. Twice, in summer 1995 and winter 1996 polycyclic aromatic hydrocarbons (PAH) and diesel motor emission (estimated as elemental carbon) were determined in the interior of a car (a 2-year-old VW Golf with a three-way catalytic converter) and in the passenger compartment of a subway train (below ground). On each sampling day (in total 16 daily measurements in the car and 16 in the subway) the substances were determined in the breathing zone of the passengers from 07:00 h to 16:00 h under different meteorologic conditions (winter- and summertime). The car followed the route of the subway from the western Berlin borough of Spandau to the south-eastern borough of Neukölln, and back. The sampling represented a realistic exposure model for driving in a high traffic and polluted urban area. The electric subway train (also 2 years in use) connected the same parts of Berlin (31 km underground). The mean values obtained during the two measurement periods (summer/winter) inside the car were 1.0 and 3.2 ng/m3 for benzo[a]pyrene, 10.2 and 28.7 ng/m3 for total-measured-PAHs, 14.1 and 8.2 micrograms/m3 for EC and in the subway 0.7 and 4.0 ng/m3 for benzol[a]pyrene, 30.2 and 67.5 ng/m3 for total PAHs, 109 and 6.9 micrograms/m3 for EC. A comparison between subway and car exposures shows significantly higher concentrations of PAHs in the subway train, which can be explained by relatively high concentrations of fluoranthene and pyrene in the subway. So far a satisfactory explanation has not been found, but one source might be the wooden railway ties which were formerly preserved with tar based products. In wintertime in both transportation systems the concentrations of beno[a]pyrene are three to four times higher than in summer corresponding to the changing of the ambient air concentrations.

[Exposure of the population to volatile organic compounds inside an automobile and a subway train]. / Exposition der Bevölkerung gegenüber flüchtigen Luftschadstoffen im Autoinnenraum und in der U-Bahn.

Air quality, in particular in urban regions, is affected by the emissions of the traffic and meanwhile for some substances motor vehicles became the dominating source. For valid quantitative risk assessment of the general population it is necessary to have informations about the main routes of exposure. Therefore in a pilot study 1994 and two times in summer 1995 and winter 1996 aromatic hydrocarbons, carbon monoxide (CO) and carbon dioxide (CO2) were determined under different meteorologic conditions inside of a car (a two year old VW-Golf with a three-way catalyst) and in a subway-train. The car route followed the subway (31 km underground) and crossed the central parts of Berlin in streets with high traffic density. The mean values for benzene obtained during the three measurement periods inside the car were 21.1/21.5 and 21.6 micrograms/m3 (daily maximum: 31.9/26.3 and 35.0 micrograms/m3) and inside the subway 8.4/5.4 and 7.4 micrograms/m3 (daily maximum: 16.0/7.4 and 10.3 micrograms/m3). The mean levels of CO in the car were 6 ppm (summer) and 5 ppm (winter) respectively, with peak concentrations of 33 and 70 ppm (10-minutes maximum). In the subway the values were 2 ppm (summer and winter); (10-minutes maximum: 5 and 12 ppm). A comparison between the two types of traffic shows three times higher concentrations of benzene inside the car. Our results demonstrate that the exposure of car occupants to benzene has to be taken into account for risk assessment. The concentration of CO inside the car is three to four times higher than in the subway train. Compared with other studies we found only low concentrations of CO inside the car.

[Polychlorinated biphenyls (PCB) in caulking compounds of buildings--assessment of current status in Berlin and new indoor air sources]. / Polychlorierte Biphenyle (PCB) in Fugendichtungsmassen von Gebäuden--Bestandsaufnahme für Berlin und neue Innenraumquellen.

Since 1990 in Berlin the building blueprints and potaining documents for public utility buildings, in particular schools and child-care centres, have been serutinised and/or buildings have been visited for the possibility of the presence of elastic sealants containing PCB. Pursuant to this, samples of the sealing material of suspected buildings were examined and air in the rooms was measured. Results of measurements (n = 410) in community rooms of schools and child-care centres were an average value of 114 ng/m3 (maximum 7.360 ng/m3) and a geometrical mean of 155 ng/m3. For measurements in schools (n = 308), the geometrical mean was 229 ng/m3, whereas in child-care centres (n = 102) it was 48 ng/m3. Within the framework of the procedural method described above regarding the investigation of suspected buildings, about 15% of the school buildings and 3% of the child-care centres had indoor air values of over 300 ng/m3 (value indicating need for taking precautions) and 5% of the school buildings had more than 3.000 ng/m3 (the value warranting an intervention, according to the now defunct Federal Health Office). No values over 3.000 ng/m3 have been measured up to now in the community rooms of child-care centres. The investigations carried out throughout the Berlin Borough of Tiergarten of all school and child-care centre buildings yielded the results that about 13% of the schools and about 4% of the child-care centres had rooms with air values above 300 ng/m3. Only one school (4%), but none of the child-care centres investigated had values of more than 3.000 ng/m3. We are of the opinion that this proves the need for the creation of an on-target survey of the concrete pollution situation and short-term adoption of exposure-reducing measures or renovations. In any case the exposure of children to this toxicologically suspect substance by this additional way of pollution must be kept as low as possible. In addition to the description of a recently concluded PCB renovation in a school building, another indoor source of pollution is presented which was unknown to date. This is sealing material containing PCB which insulates the pipes of a heating system laid as an insulating floorcover strip near the wall. In the 21 classrooms of the school building, the indoor air concentration in 16 classrooms was 1.000-3.000 ng/m3 and in 5 rooms it was greater than 3.000 ng/m3, with a maximum value of 8.000 ng/m3. In addition, it could be proved for the first time that sealing materials containing PCB were used in the external joints of residential buildings and resulted in indoor air pollution of up to 1.000 ng/m3. The fact that the PCB was also found in sealants which were proved to have been processed even at the beginning of the 1990s, may be of special importance. Up to now, such recent use had always been excluded. Within the framework of the search for contaminated buildings, the time limit regarding the date of construction of the building is no longer adequate. It can be seen from this case in an exemplary fashion, that the removal of waste of the sealants (containing PCB) for the purpose of environmental care is still associated with great problems.

[PCB in sealants: experience and results of procedures in Berlin and decontamination of a school. II. Follow-up of PCB decontamination and evaluation of individual decontamination steps]. / PCB in Dichtungsmassen: Erfahrungen und Ergebnisse bei Vorgehen in Berlin und Sanierung einer Schule. Teil II. Verlauf einer PCB-Sanierung und Beurteilung einzelner Sanierungsschritte.

A general survey of the procedure of the restoration of a school building is presented. The effects of several measures (i.e. ventilation) and restoration steps as well of problems of removal of PCB containing materials and financial charges are discussed and evaluated. It was possible to reduce the indoor air contamination below the value of 300 ng/m3 by removal of the PCB-containing sealants and sealing the secondary contaminated walls with appropriate materials.

[PCB caulking sealants--experiences and results of measures in Berlin and decontamination of a school (Part I)]. / PCB in Dichtungsmassen--Erfahrungen und Ergebnisse bei Vorgehen in Berlin und Sanierung einer Schule (Teil I).

PCB contamination of indoor air in public buildings by elastic sealants has proved to be a serious problem in West Berlin. Besides a general survey and introduction into the toxicological problem the procedure and experiences in Berlin are presented. Besides a proposal of a catalogue of several preventive measures, sampling and analytical methods are also described. During the control of about 220 buildings, 40 turned out to be PCB-contaminated, mostly gymnastic halls (30). In former East Berlin no PCB contamination by elastic sealants is known so far. In part 2 experiences and results of a restoration of a school-building are reported.