Richtwerte für C9 - C15-Alkyl-benzole in der Innenraumluft

The German Ad-hoc Working Group on Indoor Guidelines of the Indoor Air Hygiene Committee and of the Supreme State Health Authorities is issuing indoor air guide values to protect public health. The data base of human studies is insufficient for the health evaluation of C9-C15-alkylbenzenes in indoor air. Therefore, indoor air guide values are based on animal studies with inhalation exposure to individual alkylbenzenes. The guide values are derived from a chronic inhalation study with isopropylbenzene in rats, in which toxic effects in the nasal respiratory epithelium were observed. A BMCL10 of 370 mg/m3 was calculated. Extrapolation to continuous exposure, applying an interspecies factor of 2.5, a factor of 10 for interindividual variability, and a factor of 2 to account for the higher respiratory rate of children compared to adults, a health hazard guide value (RW II) of 1 mg isopropylbenzene/m3 indoor air is obtained. A health precaution guide value of 0.1 mg isopropylbenzene/m3 indoor air is recommended. Same values were derived on the basis of toxic effects of trimethylbenzenes; the data base is insufficient for the derivation of specific indoor air guide values for higher alkyl benzenes. Therefore, the Ad-hoc Working Group is issuing the indoor air guide values for the sum of C9-C15 alkylbenzenes.     

Richtwerte für 1-Butanol in der Innenraumluft

The German Ad Hoc Working Group on Indoor Guidelines of the Indoor Air Hygiene Committee and the States’ Supreme Health Authorities is issuing indoor air guide values to protect public health. No human studies of sufficient quality are available for the evaluation of 1-butanol in indoor air. In a well-documented oral study on reproduction toxicity in rats, assessed as reliable, impairment of embryo development was observed. Benchmark modeling of the study data by US-EPA revealed a BMDL₁₀ of 26.1 mg/kg b.w. per day. The working group used this BMDL₁₀ as the point of departure for the derivation of the guide value II. Considering a human respiration rate of 20 m³ per day and a human body weight of 70 kg, this dose was converted into an inhalative concentration. Applying a factor of 0.6 to account for the inhalative absorption rate, an allometric extrapolation factor from rat to human (factor 4), an interspecies factor of 2.5 for toxicodynamics, and a factor of 10 to account for individual differences (intraspecies factor), results in a health hazard guide value (RW II) of 2 mg 1-butanol/m³. The benchmark dose calculation of the same study generated a BMDL₀₅ of 12.4 mg/kg b.w. per day. Applying the same assessment factors as for RW II, a precautionary guide value (RW I) of 0.7 mg 1-butanol/m³ indoor air is calculated.     

Richtwerte für Glykolether und Glykolester in der Innenraumluft

The German Ad-hoc Working Group on Indoor Guidelines of the Indoor Air Hygiene Committee and of the Supreme State Health Authorities is issuing indoor air guide values to protect public health. For health evaluation of glycol ethers and glycol esters in air, the entire group of substances with data for 47 compounds was analysed in order to gain a unique assessment. For some glycol ethers reproductive and haematological effects are of central interest, whereas for others effects on liver and kidneys are crucial. Moreover, some glycol ethers were also shown to cause irritation of the respiratory tract. Fourteen compounds could be characterized either by relevant inhalation studies or by analogies drawn to strongly related substances. For these compounds individual guide values were derived, the respective guide value I ranging from 0.02–2 mg/m³ (Tab. 2). The derivation of guide values considered the time exposure of the population as compared to working people or animal studies. The duration of the respective study, the interindividual variability—by a factor of 10—and the enhanced respiratory rate in children as compared to adults—by a factor of 2—were further taken into account. To allow for extrapolation from animal to human exposure differences in toxicodynamics were considered by a factor of usually 2.5. For compounds with insufficient data a default guide value II and I of 0.05 and 0.005 ppm, respectively, was recommended based on the statistical analysis of the available data of all glycol ethers. In order to achieve a total evaluation of all glycol ethers and glycol esters found in indoor air the proportional concentrations of each compound divided by the respective guide value were aggregated to give a total guide value. The total guide values are regarded to be complied with if their respective value falls below 1.     

Richtwerte für monocyclische Monoterpene (Leitsubstanz d-Limonen) in der Innenraumluft. Mitteilung der Ad-hoc-Arbeitsgruppe Innenraumrichtwerte der Innenraumlufthygiene-Kommission des Umweltbundesamtes und der Obersten Landesgesundheitsbehörden

The German Working Group on Indoor Air Guidelines of the Federal Environment Agency and the States' Health Authorities is issuing indoor air guide values to protect public health. For health evaluation of monocyclic monoterpenes in indoor air valid inhalation studies are missing. Therefore, indoor air guide values have to be derived from animal feeding studies with limonene and chronic exposure (feeding: 5 days per week over two years). The Lowest Adverse Effect Level based on histological lesions of liver tissue was observed with 500 mg limonene/kg bw x day. The extrapolation to continuous exposure (7 days/week) corresponds to a dose of 357 mg/kg x d (LOAEL). The indoor air guide values are calculated using 20 m3 as rate of inhalation per day, a standard body weight of 70 kg for man, the standard factors of 10 x 10 for interspecies and interindividual variability, a factor of two for the specific physiology of children (higher breathing rate compared to adults) and an absorption factor of 63% for inhalative incorporation of limonene. A health hazard guide value (RW II) of 10 mg limonene/m3 in indoor air and a health precaution guide value (RW I) of 1 mg limonene/m3 are derived. The precaution guide value of 1 mg/m3 coincidences with the lower range of reported odour thresholds of limonene.     

Richtwerte für Toluol und gesundheitliche Bewertung von C7-C8-Alkylbenzolen in der Innenraumluft

The German Committee on Indoor Guide Values issues indoor air guide values to protect public health. For health evaluation of inhaled toluene a number of valid studies in humans is available. Toluene is a neurotoxic substance and the guide values are based on deficits in neurobehavioural tests observed at workers with chronic exposure of 337 mg toluene/m³. For the derivation of guide values the assumed continuous exposure is considered by a factor of 4.2, the interindividual variability by a factor of 10 and the elevated respiratory rate in children as compared to adults by a factor of 2. The resulting health hazard guide value (guide value II) is 4 mg toluene/m³. As the difference to the former indoor air guide value of 1996 for toluene is only caused by the slightly changed extrapolation factor for continuous exposure, the committee maintains the guide value II of 3 mg toluene/m³ and the precautionary guide value (guide value I) of 0.3?mg toluene/m³ indoor air. As all C7-C8 alkylbenzenes are neurotoxic the committee evaluates toluene, ethylbenzene and the xylenes as a group. In order to achieve a total evaluation the ratios of concentration and respective guide value of each compound were added. The total guide values I and II are regarded to be complied with if the corresponding sum falls below 1.     

Richtwerte für Acetaldehyd in der Innenraumluft

The German Ad-hoc Working Group on Indoor Guidelines of the Indoor Air Hygiene Committee and the States’ Supreme Health Authorities is issuing indoor air guide values to protect public health. No suitable human studies are available for health evaluation of acetaldehyde in indoor air. In a well-documented subchronic inhalation animal study with rats assessed as reliable, local irritation effects were observed in nasal epithelia, most prominently in the olfactory epithelium with loss of olfactory neuronal cells. This study leads to a LOAEC of 48 mg acetaldehyde/m³ for continuous exposure for the endpoint nasal epithelium degeneration. By applying an interspecies factor of 1, a factor of 10 for interindividual variability, and a factor of 2 to account for the higher respiratory rate of children compared to adults, a health hazard guide value (RW II) of 1 mg acetaldehyde/m³ is obtained. A health precaution guide value (RW I) of 0.1 mg acetaldehyde/m³ is recommended.     

Guide values for indoor air: update of the German risk assessment procedure (basic scheme)

In order to harmonize recommendations on the evaluation of indoor air contamination by means of guide values, the Ad-hoc Working Group of the Indoor Air Hygiene Commission of the German Federal Environment Agency and of the Supreme State Health Authorities (IRK / AOLG Ad-hoc working group) has updated the procedures for toxicologically derived indoor air guide values for individual substances or groups of substances. In general two guide values are proposed by the committee. Guide value II (RW II) is an adverse effect-related value, based on current toxicological and epidemiological knowledge of a substance's effect threshold, usually the LOAEC or a benchmark concentration from human or animal studies. Guide value I (RW I) represents the concentration of a substance in indoor air for which, when considered individually, there is no evidence at present that even lifelong exposure is expected to have any adverse health impacts. Individual steps in the derivation of guide value II are: i) identification of the critical study and the Point of Departure (POD), conversion from short term to continuous exposure by adjustment for ii) study length (subacute - subchronic - chronic) and iii) exposure duration (hours/day and days/week), extrapolation from animal to man by iv) interspezies variability (allometric, toxicokinetic and dynamic factors), consideration of sensitive individuals by v) intraspecies variability (kinetic and dynamic factor), and vi) physiologic differences within the population( i.e. children factor), and finally vii) consideration of the quality of database. The quality of the pivotal study is assessed according to the criteria proposed by Klimisch et al. (1997). The assessment factors have been harmonized with recent recommendations by WHO (IAQG 2010) and ECHA guidance document R 8. RW I is derived from RW II by introduction of an additional factor (usually 10) but can also be derived if no reliable LOAEC is available from a "No observed adverse effect concentration" (NOAEC).A template containing the key information on the chemical and the critical study and transparently presenting the assessment factors and derivation of the guide values and a glossary of terms complete the recommendation.     

Richtwerte für Ethylbenzol in der Innenraumluft

The German Working Group on Indoor Guidelines of the Federal Environment Agency and the States' Health Authorities is issuing indoor air guide values to protect public health. No human studies are available for health evaluation of ethylbenzene in indoor air. In a well documented subchronic inhalation animal study assessed as reliable, ototoxic effects were observed (LOAECsubchronic = 870 mg/m3). The Working Group assessed a LAEC of 186 mg ethylbenzene/m3 for the endpoint ototoxicity. By applying a factor of 2 to extrapolate from subchronic to chronic exposure, an interspecies factor of 2.5, a factor of 10 for interindividual variability, and a factor of 2 to account for the higher respiratory rate of children compared to adults, a health hazard guide value (RW II) of 2 mg ethylbenzene/m3 is obtained. A precautionary guide value (RW I) of 0.2 mg ethylbenzene/m3 is recommended.     

Richtwerte für 1-Methyl-2-pyrrolidon in der Innenraumluft

The German Ad-hoc Working Group on Indoor Guidelines of the Indoor Air Hygiene Committee and the States’ Supreme Health Authorities is issuing indoor air guide values to protect public health. No human studies of sufficient quality are available for health evaluation of 1-methyl-2-pyrrolidone in air. In a well-documented chronic inhalation toxicity study in rats significant impairment of weight gain development has been observed (LOAEC?=?400 mg/m³). The Working Group used this LOAEC as the point of departure for the derivation of guide value II. The conversion of repeated inhalation to continuous exposure (6–24 h; 5–7 days) used a factor of 5.6. By applying an interspecies factor of 2.5 for toxicodynamics, a factor of 10 to account for individual differences and an additional factor of 2 to include sensitive subgroups, results in a health hazard guide value (RW II) of 1 mg 1-methyl-2-pyrrolidone/m³ indoor air (rounded). By using the NOAEC of 40 mg/m³ from the same study and applying the same assessment factors as above a precautionary guide value (RW I) of 0.1 mg 1-methyl-2-pyrrolidone/m³ is calculated.     

Indoor air guide values for phenol

The German Working Group on Indoor Guidelines of the Federal Environment Agency and the States′ Health Authorities is issuing indoor air guide values to protect public health. For health evaluation of phenol in indoor air a qualified working-place study emphasizing the POD hemo- and hepatotoxicity as well as results of a limited inhalation-study which underline neurological effects on rats were used. The Working Group assessed a lowest observed adverse effect level of 21 mg Phenol/m3 in the working-place study and 100 mg Phenol/m3 in the animal-based study. Both toxicological derivatives come to the same result but the working-place study was preferred. By applying a factor of 10 for interindividual variability, a factor of 4.2 for the different exposing-time of workers and usual population and a modifying factor of 2 regarding children a health hazard guide value (RW II) of 0.2 mg phenol/m3 is obtained. A health precaution guide value of 0.02 mg phenol/m3 is recommended.     

Indoor air guide values for 2-furaldehyde

The German Working Group on Indoor Guidelines of the Federal Environment Agency and the States' Health Authorities is issuing indoor air guide values to protect public health. For health evaluation of 2-furaldehyde in air valid human studies are missing. In a subacute inhalation study well documented and assessed as reliable respiratory epithelial lesions such as squamous metaplasia and atypical hyperplasia were observed. The Working Group assessed a lowest observed adverse effect level of 20 mg 2-furaldehyde/m3 for the endpoint irritation following subacute exposure and extrapolated to a chronic lowest adverse effect level of 1 mg 2-furaldehyde/m3. By applying a factor of 5 for interindividual variability of irritation and a modifying factor of 2 regarding data gaps especially for children a health hazard guide value (RW II) of 0.1 mg 2-furaldehyde/m3 is obtained. A health precaution guide value of 0.01 mg 2-furaldehyde/m3 is recommended.     

Air pollution in internal environments and sick building syndrome

Indoor Air Quality (IAQ) emerged as a science from the 1970s onwards with the energy crisis and the subsequent construction of sealed buildings (without natural ventilation). This mainly occurred in developed countries and it soon came to public attention that lower levels of air exchange in these environments was the main culprit for the increase in concentration of indoor air pollutants. It is common knowledge that ventilation is one of the principal factors that interfere with air quality in indoor environments and that the occupants contribute to the pollution of these environments with their activities. Furthermore, poor indoor air quality is associated with some diseases (cough, rhinitis, allergy, etc.) and with Sick Building Syndrome (SBS). For sampling of the indoor contaminants there are several methodologies, available including passive monitoring systems, active and automatic systems. To ensure a healthy indoor environment, the application of specific legislation needs to be reconciled with research and fostering awareness among the occupants of such buildings. This survey seeks to identify the different contaminants found in internal environments, their effects on human health and the methodologies available for sampling them.     

Richtwerte für Kresole in der Innenraumluft

AbstractThe Ad-hoc Working Group on Indoor Guidelines of the Indoor Air Hygiene Committee and of the Supreme State Health Authorities in Germany is issuing indoor air guide values to protect public health. For health evaluation of cresols in indoor air upper airway irritation was seen as critical effect. Unfortunately, valid inhalation studies were not available. Therefore, results of a recent oral long term study with a mixture of cresols in male rats were used. The Working Group selected a BMDL10 of 13.9 mg cresols per kg body weight and day assessed by US-ATSDR as a point of departure. A path-to-path-extrapolation involved a breathing rate of 20 m3 per day, a body weight of 70 kg and an oral resorption rate of 50%. A factor of 10 each for interspecies and intraspecies variability, respectively, and a modifying factor of 2 regarding physiological differences in children were applied. Since data from inhalation studies indicated more pronounced airway irritation than data from oral studies an additional factor of 2 was introduced. A health hazard value (RW II) of 0.05 mg cresols/m3 and a precautionary value (RW I) of 0.005 mg cresols/m3 are recommended.     

Indoor air quality and health in offices and other non-industrial working environments

BACKGROUND: Over the last 30 years, transformation of indoor environments--in particular in office blocks--has been associated with complaints from workers of discomfort, malaise and even diseases termed Building Related Illnesses (BRI) which are classified as specific (e.g. Legionnaire disease, asthma, hypersensitivity pneumonia) or non-specific (e.g. the Sick Building Syndrome). METHODS: A review was made of data from international public health organisations, epidemiological, clinical and experimental studies and congress proceedings from 1990 to 2006 on the topic of indoor air quality and health in modern, non-industrial workplaces. RESULTS: Studies focused on ventilation, temperature and air humidity and specific pollutants such as Volatile Organic Compounds, particules asbestos fibres, environmental tobacco smoke, radon and biological agents. We can now measure microclimate parameters and many indoor air pollutant levels as well as their effects on health; we can also formulate indications of threshold and guideline values for some of these and make a preventive assessment for toxic emissions from construction and furnishing materials. A stepwise, multi-disciplinary approach--with the specialist in occupational medicine playing a major role--is most suitable for dealing with BRI and the effects of poor indoor air quality on health. CONCLUSIONS: Better criteria are needed to study emission of substances into the indoor environment, adequacy of ventilation, additive or synergistic effects of mixtures of chemicals and toxicity of micro-organism decomposition products. Objective clinical tests to assess the effects of indoor pollutants on health and indices for Indoor Environmental Quality in assessing buildings need to be improved.     

Clearing the air: a model for investigating indoor air quality in Texas schools

This pilot project focused on the assessment of indoor air quality at a local high school in Galveston, Texas, using methods based on guidelines for the U.S. Environmental Protection Agency's Indoor Air Quality Tools for Schools program. Tools for Schools, developed for evaluating and ensuring acceptable air quality for schools, takes a low-cost, minimal-involvement, primarily educational approach. The authors also compared the findings from this approach with the results of an air-sampling program. The overall goal was to determine if use of Tools for Schools was sufficient to identify conditions with the potential to cause adverse health effects. The primary objectives were to 1) establish an indoor air quality committee for the school to implement Tools for Schools assessments and management strategies, 2) collect air quality data in high-risk areas identified within the school by the indoor air quality committee, 3) collect outdoor air quality data at or in close proximity to the school, and 4) develop methods and instruments for assessing environmental risks associated with daily school attendance. Data were gathered on levels of formaldehyde and other volatile organic compounds (VOCs), ozone, particulate matter (PM10), mold, relative humidity, and temperature. Data values for each sampled pollutant were compared with federal standards, recommended values established by the American Conference of Governmental Industrial Hygienists for non-industrial populations, and effects screening levels developed by the Texas Commission on Environmental Quality. Levels of all VOCs except formaldehyde were found to be well within guidelines, as were ozone and particulate-matter levels. Mold, however, was widespread, including both common species and species associated with allergy and asthma, such as Aspergillus and Alternaria. In general, Tools for Schools provides an excellent foundation for a school indoor air quality program, although the authors did find it necessary to streamline data collection and did find that mold with the potential for adverse health effects was present, albeit not visible in some areas.     

建筑室内生物污染及健康影响的研究进展

室内生物污染对人体健康的影响越来越受到人们的重视。室内生物污染物包括细菌、病毒、真菌、尘螨和花粉等,其来源也具有多样性。国内外的研究发现,生物污染物在公共场所、学校、家庭居室等不同类型的建筑内的污染非常普遍,有时水平还相当高。室内生物性污染对人们的健康会造成一定的影响,如引起传染性疾病,导致过敏性疾病,甚至还可能致癌和致突变。该文对建筑室内生物污染及健康影响的研究进展进行了综述。     

Beurteilung von Innenraumluftkontaminationen mittels Referenz- und Richtwerten

Assessment of indoor air contaminants is recommended to be based on toxicologically derived guideline values (GV, German: Richtwerte, RW) for single substances, TVOC levels, and statistically derived reference values. This recommendation refers to private and public indoor environments and workplaces without production-related handling of hazardous substances. According to the working group's current assessments, the GV I (RW I) is a concentration below which no adverse health effects are to be expected even at life-long exposure to the respective single substance. Concentrations exceeding GV II (RW II) are likely to represent a threat to health, especially for sensitive people. According to a general scheme, guideline values I and II have been derived for - toluene (0.3 and 3 mg/m(3)), - pentachlorophenol (0.1 and 1 microg/m(3)), - dichloromethane (0.2 and 2 mg/m(3)), - styrene (0.03 and 0.3 mg/m(3)), - tris(2-chloroethyl)phosphate (0.005 and 0.05 mg/m(3)), - bicyclic terpenes (0.2 and 2 mg/m(3), - naphthalene (0.002 and 0.02 mg/m(3)), - aliphatic hydrocarbons (0.2 and 2 mg/m(3)). In case of concentrations exceeding GV II, immediate measures are to be taken, among them restrictions of the time spent in the room and measures to remove or reduce emission sources. At levels between GV I and GV II, increased air exchange and cleaning are adequate first steps. However, if concentrations continue to exceed GV I, more intensive measures are recommended. Based on the TVOC concept (cf. Seifert 1990), 5 stages with specific recommendations are defined provided that the special GVs ("Richtwerte") are not exceeded: Level 1: TVOC < 0. 3 mg/m(3): No hygienic objections, target value. Level 2: TVOC > 0.3-1 mg/m(3): No relevant objections, but increased ventilation recommended. Level 3: TVOC > 1-3 mg/m(3): Concerning hygienic aspects, some objections due to elevated concentration level. Upper range for a maximum of 12 months. Search for sources, increased ventilation recommended. Level 4: TVOC > 3-10 mg/m(3): Major objections. Should not be tolerated for > 1 month. Restricted use only. Search for sources, intensified ventilation necessary. Level 5: TVOC > 10-25 mg/m(3): Situation not acceptable. Use only if unavoidable and then for short periods (hours) only with intensified ventilation. An assessment based on reference values does not imply any health risk assessment. It only provides information on exposure relative to the exposure of the reference group. For comparison, regularly updated and representative reference values are recommended. In case of exceeded reference values, plausibility should be checked. Considering concentration and known toxicological data, health relevance should be estimated in order to decide on the necessity of measures to be taken. Since results of indoor air measurements are strongly influenced by sampling strategy, ventilation and climatic factors, recommendations are given in order to standardise sampling procedures and conditions.     

Assessment of indoor air problems at work with a questionnaire

Aims: To assess the extent of indoor air problems in office environments in Finland.

Methods: Complaints and symptoms related to the indoor environment experienced by office workers were collected from 122 workplaces in 1996–99 by using the modified Indoor Air Questionnaire established by the Finnish Institute of Occupational Health. Altogether 11 154 employees took part in the survey.

Results: The most common problems were dry air (35% of the respondents), stuffy air (34%), dust or dirt in the indoor environment (25%), and draught (22%). The most common work related symptoms were irritated, stuffy, or runny nose (20%), itching, burning, or irritation of the eyes (17%), and fatigue (16%). Women reported indoor air problems and work related symptoms more often than men. Allergic persons and smokers reported indoor air problems more often, and experienced work related symptoms more often than non-allergic persons and non-smokers.

Conclusions: The complaints and work related symptoms associated with indoor air problems were common in office workers. The present questionnaire is a suitable tool for the occupational health personnel in investigating indoor air problems and the data of the survey can be used as a reference when the results of a survey at work are being analysed.

     

Indoor Air Distribution of Nitrogen Dioxide and Ozone in Urban Hospitals

Indoor air pollution has recently become a public concern in Taiwan. People recognize that indoor air quality (IAQ) may be more important than outdoor air quality because they spend over 80% of their time indoors. IAQ could affect health and comfort of building occupants. The objectives of this study are (1) to characterize the indoor concentrations of selected air pollutants at two hospitals in Hsinchu, Taiwan, (2) to evaluate the potential indoor sources of pollutants in these selected hospitals and their indoor/outdoor relationships, and (3) to compare pollutant concentrations with values published in other studies. A significant between-hospital difference in average indoor concentration of nitrogen dioxide and 54.14, 32.69 ppb for Hospital A and B, respectively (p < 0.05). Indoor nitrogen dioxide concentration was significantly positively correlated with outdoor nitrogen dioxide concentration, PM₁₀ concentration, and traffic flow (r = 0.91, 0.65 and 0.72, respectively). The ozone level was also lower in our hospitals than 30 ppb standard.     

挥发性有机污染物在室内环境中的化学反应及其健康影响

室内环境中存在大量的挥发性有机污染物(VOCs),在O3和NO2存在的情况下,各污染物之间可能发生各种各样的化学反应,这些反应严重地影响了室内空气质量,造成室内人员的健康损害。该文论述了室内可能存在的主要化学反应,以及其带来的健康问题,并概括了相关研究的内容和存在的问题。对室内环境中VOCs的化学反应进行研究对于人体健康非常重要,有助于改进室内空气质量标准和建立建筑材料“生态标志”。