The adverse health effects of biological aerosols, other aerosols, and indoor microclimate on asthmatics and nonasthmatics

Asthmatic and nonasthmatic families in a representative community population sample have been monitored over a 2-year period using daily diaries. Simultaneous micro-indoor and outdoor monitoring has been conducted in a representative sample of houses for air pollutants, pollen, fungi, algae, and climate. Macromonitoring of air pollutants and pollen was conducted simultaneously. The relationship of indoor to outdoor and micro to macro factors can be demonstrated. Acute symptoms were strongly related to age, weakly related to sex, and not related to smoking habits. The qualitative relationship of these micro and macro factors to symptoms in asthmatic and nonasthmatic families have been explored. Suspended particulate matter and pollen were related to symptoms in asthmatics and nonasthmatics. Fungi might be related to symptoms as well. The use of gas stoves is qualitatively related to symptoms. Algae and other contaminants of evaporative coolers do not appear to be important in producing symptoms. More complex statistical analyses are required to determine interactions of these factors. Distinction has to be drawn between infectious episodes, allergic episodes, nonallergic but similar episodes, and asthmatic attacks. This study demonstrates the need for further investigations in this area.     

Emission of ammonia from indoor concrete wall and assessment of human exposure

Addition of urea-based antifreeze admixtures during cement mixing can make it possible to produce concrete cement in construction of buildings in cold weather; this, however, has led to increasing indoor air pollution due to continuous transformation and emission from urea to gaseous ammonia in indoor concrete wall. It is believed that ammonia is harmful to human body and exposure to ammonia can cause some serious symptoms such as headaches, burns, and even permanent damage to the eyes and lungs. In order to understand the emission of ammonia from indoor concrete wall in civil building and assess the health risk of people living in these buildings, the experimental pieces of concrete wall were first prepared by concreting cement and urea-based antifreeze admixtures to simulate the indoor wall in civil building in this work. Then environmental chamber was adopted for studying the effect of temperature, relative humility and air exchange rate on emission of ammonia from experimental pieces of concrete wall. Also the field experiment was made at selected rooms in given civil buildings. Exposure and potential dose of adult and children exposed to indoor/outdoor ammonia in summer and in winter are calculated and evaluated by using Scenario Evaluation Approach. The results indicated that high air exchange rate leads to decreased ammonia concentration, and elevation of temperature causes increasing ammonia concentration and volatilizing rate in chamber. The complete emission of ammonia from the wall containing urea-based antifreeze admixtures needs more than 10 years in general. Ventilating or improving air exchange can play a significant role in reducing ammonia concentration in actual rooms in field experiments. Urea-based antifreeze admixtures in concrete wall can give rise to high exposure and potential dose, especially in summer. Generally, adults have a high potential dose than children, while children have personal average dose rate beyond adults in the same conditions.     

Indoor air pollution due to organic gases and vapours of solvents in building materials

The emission of organic gases and vapours of solvent type from 42 commonly used building materials was measured under standard atmospheric conditions. An average of 22 compounds was found in the air around each building material, and the total concentration of gases and vapours was from 0.01 to 1410 mg/m³. The average arithmetic emission rate was 9.5 mg/m² h, and 52 different compounds were identified. A mathematical model was established for the indoor air concentrations of pollutants originating from building materials. The model was tested on three model rooms constructed from the materials investigated. The calculated total air concentrations of gases and vapours in the three rooms ranged from 1.6 to 23.6 mg/m³, and the number of compounds in the air from 23 to 32. These concentrations and number of compounds did not differ from those found in actual rooms similar in size and construction to the model rooms. The risks of health effects due to the compounds identified from the building materials were investigated, and criteria for future air quality standards are discussed. It is concluded that the possibility of negative health effects cannot be neglected, especially not for the more sensitive minority of the general population.     

The influence of the cigarette smoke pollution and ventilation rate on alpha-activities per unit volume due to radon and its progeny

Alpha and beta activities per unit volume air due to radon, thoron and their decay products were evaluated in the air of various cafe rooms polluted by cigarette smoke. Both CR-39 and LR-115 type II solid state nuclear track detectors (SSNTD) were used. Equilibrium factors between radon and its progeny and thoron and its daughters have been evaluated in the air of the studied cafe rooms. The committed equivalent doses due to short-lived radon decay products were determined in different regions of the respiratory tract of non-smoker members of the public. The influence of cigarette smoke pollution, ventilation rate and exposure time on committed equivalent dose in the respiratory systems of non-smokers was investigated. Committed equivalent doses ranged from 1.15 x 10(-11)-2.7 x 10(-7) Sv.y(-1)/h of exposure in the extrathoracic region and from 0.8 x 10(-12)-1.7 x 10(-8) Sv.y(-1)/h of exposure in the thoracic region of the respiratory tract of non-smokers.     

Negatively-charged air conditions and responses of the human psycho-neuro-endocrino-immune network

BACKGROUND: Against increasing environmental adverse effects on human health such as those associated with water and ground pollution, as well as out- and indoor air conditions, trials were conducted to support and promote human health by improving the indoor air atmosphere. This study was performed to estimate the effect of negatively-charged air conditions on human biological markers related to the psycho-neuro-endocrino-immune (PNEI) network. OBJECTIVES: After construction of negatively-charged experimental rooms (NCRs), healthy volunteers were admitted to these rooms and control rooms (CTRs) and various biological responses were analyzed. METHODS: NCRs were constructed using a fine charcoal coating and applying an electric voltage (72 V) between the backside of walls and the ground. Various biological markers were monitored that related to general conditions, autonomic nervous systems, stress markers, immunological parameters and blood flow. RESULTS: Regarding the indoor environment, only negatively-charged air resulted in the difference between the CTR and NCR groups. The well-controlled experimental model-room to examine the biological effects of negatively-charged air was therefore established. Among the various parameters, IL-2, IL-4, the mean RR interval of the heart rate, and blood viscosity differed significantly between the CTR and NCR groups. In addition, the following formula was used to detect NCR-biological responses: Biological Response Value (BRV)=0.498+0.0005 [salivary cortisol]+0.072 [IL-2]+0.003 [HRM-SD]-0.013 [blood viscosity]-0.009 [blood sugar]+0.017 [pulse rate]. CONCLUSIONS: Negatively-charged air conditions activated the immune system slightly, smoothened blood flow and stabilized the autonomic nervous system. Although this is the first report to analyze negatively-charged air conditions on human biological responses, the long-term effects should be analyzed for the general use of these artificial atmospheres.     

Indoor climate in low-ventilated day-care institutions

Measurements of indoor atmospheric environment were carried out in a day nursery and a kindergarten, in which natural air infiltration supplied the rooms with only 1–2 m³ fresh air per person and hour under the prescribed occupancy. The exposure situation from the field was duplicated under controlled conditions in a climate chamber. The results indicate unacceptably high concentrations of carbon dioxide, and emphasize the need for more elaborate building design in airtight buildings.     

Volumetric assessment of airborne fungi in two sections of a rural indoor dairy cattle shed

There is increasing concern about the exposure to fungal aerosols in occupational environments and associated respiratory allergic diseases and asthma. A large number of people work in cattle sheds around the world, pulmonary function impairments and higher frequency of respiratory symptoms have been reported in dairy farmers; however, it appears that adequate information on the fungal aerosols from the cattle sheds are largely lacking. Volumetric assessment of airborne culturable and nonculturable fungal spores was performed in two sections of a large rural indoor cattle shed of West Bengal, India for 2 consecutive years. An Andersen Two Stage Viable Sampler was used for sampling culturable fungi and a Burkard Personal Slide Sampler was used to collect the total airborne fungal spores including both the culturable and nonculturable types. A total of 31 spore types and 35 types of viable colony-forming units were recorded. Average concentration range of total fungal spores was 233-2985/m(3) and concentration of viable colony-forming units ranged between 165 and 2225 CFU/m(3). Burkard Sampler showed higher frequencies of Aspergilli/Penicilli, Cladosporium, Alternaria, and smut spores. Andersen Sampler showed the prevalence of Aspergillus niger, Aspergillus flavus and Cladosporium cladosporioides colonies. Some recorded fungi were earlier reported as allergenic, toxic, and pathogenic for occupational workers as well as cattle population. Higher concentration levels of airborne total and culturable fungal spores were recorded during the months of November through February (winter) and June through September (late summer and rainy season).     

Emission modelling and validation of VOCs' source strengths in air-conditioned office premises

An emission model for indoor volatile organic compounds (VOCs) based on mass balance considerations has been presented and validated under steady state conditions. Comparison were made for the measured and predicted concentrations of 37 selected VOCs and TVOC through a case intervention study on the filters of the ventilation system in a new commercial air-conditioned office building. The intervention involved replacing media filters with electronic and carbon filtration. TVOC and 37 compounds selected for their health and comfort impact, representation of major chemical classes that occur in indoor air and their utility as markers of pollution sources were studied. The concentration levels predicted by the model were compared with actual measurements. Twenty-five target compounds and the TVOC were adequately described by the model where the measured concentrations were in agreement with the predicted concentrations. Modeling of the remaining 12 compounds was found to be affected by the emission rates that were occupant related.     

Flame retardants in indoor dust and air of a hotel in Japan

Occurrence of flame retardants (FRs) in the indoor environment of highly flame-retarded public facilities is an important concern from the viewpoint of exposure because it is likely that FRs are used to a greater degree in these facilities than in homes. For this study, brominated flame-retardants (BFRs) and organophosphate flame-retardants and plasticizers (OPs), and brominated dibenzo-p-dioxins/furans (PBDD/DFs) were measured in eight floor dust samples taken from a Japanese commercial hotel that was assumed to have many flame-retardant materials. Concentrations of polybrominated diphenylethers (PBDEs) and hexabromocyclododecanes (HBCDs) varied by about two orders of magnitude, from 9.8–1700 ng/g (median of 1200 ng/g) and from 72–1300 ng/g (median of 740 ng/g), respectively. Concentrations of the two types of BFRs described above were most dominant among the investigated BFRs in the dust samples. It is inferred that BFR and PBDD/DF concentrations are on the same level as those in house and office dust samples reported based on past studies. Regarding concentrations of 11 OPs, 7 OPs were detected on the order of micrograms per gram, which are equivalent to or exceed the BFR concentrations such as PBDEs and HBCDs. Concentrations of the investigated compounds were not uniform among dust samples collected throughout the hotel: concentrations differed among floors, suggesting that localization of source products is associated with FR concentrations in dust. Passive air sampling was also conducted to monitor BFRs in the indoor air of hotel rooms: the performance of an air cleaner placed in the room was evaluated in terms of reducing airborne BFR concentrations. Monitoring results suggest that operation of an appropriate air cleaner can reduce both gaseous and particulate BFRs in indoor air.     

Contribution of (222)Rn-bearing water to indoor radon and indoor air quality assessment in hot spring hotels of Guangdong, China

This study investigates the contribution of radon (²²²Rn)-bearing water to indoor ²²²Rn in thermal baths. The ²²²Rn concentrations in air were monitored in the bathroom and the bedroom. Particulate matter (PM, both PM₁₀ and PM_2.5) and carbon dioxide (CO₂) were also monitored with portable analyzers. The bathrooms were supplied with hot spring water containing 66-260 kBq m⁻³ of ²²²Rn. The results show that the spray of hot spring water from the bath spouts is the dominant mechanism by which ²²²Rn is released into the air of the bathroom, and then it diffuses into the bedroom. Average ²²²Rn level was 110-410% higher in the bedrooms and 510-1200% higher in the bathrooms compared to the corresponding average levels when there was no use of hot spring water. The indoor ²²²Rn levels were influenced by the ²²²Rn concentrations in the hot spring water and the bathing times. The average ²²²Rn transfer coefficients from water to air were 6.2 × 10⁻⁴-4.1 × 10⁻³. The 24-h average levels of CO₂ and PM₁₀ in the hotel rooms were 89% and 22% higher than the present Indoor Air Quality (IAQ) standard of China. The main particle pollutant in the hotel rooms was PM_2.5. Radon and PM₁₀ levels in some hotel rooms were at much higher concentrations than guideline levels, and thus the potential health risks to tourists and especially to the hotel workers should be of great concern, and measures should be taken to lower inhalation exposure to these air pollutants.     

Bronchial Rn dose survey for residences

The bronchial dosimeter for Rn progeny proposed by Yu and Guan in 1998 was employed to survey the bronchial dose from Rn progeny in 30 residences in Hong Kong. An average bronchial deposition fraction of Rn progeny was obtained as 0.0334, which gave an average dose conversion factor (DCF) of 8.5 mSv WLM-1. The mean values of potential alpha energy concentration (PAEC) deposited in the tracheobronchial region (PAECT-B), total PAEC in air (PAECT), annual effective dose (E), concentration of Rn gas (RC) and annual dose conversion factor (ADCF) for all the residential sites combined were 0.11 +/- 0.05, 3.1 +/- 1.4 mWL, 1.2 +/- 0.5 mSv yr-1, 23 +/- 10 Bq m-3 and 0.055 +/- 0.020 (mSv yr-1 per Bqm-3), respectively, with air-conditioned sites (AC sites) and non-AC sites having significantly different mean ADCF values. The indoor relative humidity affected PAECT and RC with high confidence levels (> 95%).     

Indoor air quality and minimum ventilation rate

In a 30-m³ test chamber the air pollutants caused by man were measured. Variables were the number of persons and the rate of air change. During 2-h test sessions the temperature, relative humidity, carbon dioxide, and intensity of odors were measured. The relationship between the perceived odor intensities and the concentrations of carbon dioxide-independent of the number of persons and the air change rate—was observed. At air change rates of 12–15 m³/person/h, the carbon dioxide concentration was not higher than 0.15% and the odor intensity was evaluated only as a “slight annoyance.” Higher ventilation rates are necessary if smoking and increased physical activities are done in the rooms.     

The influence of ventilation on indoor/outdoor air contaminants in an office building

The air quality in a newly built preschool was investigated in a longitudinal study. Typical air contaminants emanating from building materials were determined, their variation over time (0–18 months) was measured, and the influence of the ventilation system (81%–91% recirculation of return air) on contaminant concentrations was studied. Volatile organic compounds were sampled by adsorption on porous polymer, analysed by a GC/FID system, and identified by MS. A spatial build-up in concentration (ppb or μg/m³ levels) is evident for all the organic compounds, as well as for CO₂, from the outdoor air, through the ventilation system, and through the rooms to the exhaust air. The longitudinal comparison over time shows that all the organic compounds decline in concentration mainly within the first 6 months of occupancy: 1-butanol 4–14 times, toluene and pentanal + hexanal 2–4 times, while formaldehyde remained at a constant low level of 90 ppb (110 μg/m³). It is difficult to believe that the problems of poor air quality in 100 preschools in Stockholm are caused by the organic compounds alone unless interactions occur. A preschool building needs to be gassed off during the first 6 months after its construction with no recirculation of return air allowed (outdoor air rate approx 4–5 ach). During at least 1–2 additional years, it is desired that the recirculation rate of return air is restricted, perhaps to 50%.     

Ventilation for control of indoor air quality: A case study

Dilution of indoor air contaminants with less contaminated outdoor air is the most common strategy for control of indoor air quality. Unfortunately this strategy frequently imposes a substantial energy burden. If the contaminants are associated with occupants and their activities, a ventilation control system based on the carbon dioxide level in the controlled space is shown to relieve this energy burden. A test was carried out in the Fridley, MN, Junior High School Music Department to obtain air quality, energy, and subjective response data on an Automatic Variable Ventilation System. A control system with both CO₂ and temperature inputs was devised to control the use of outdoor air. Infiltration measurements lead to a quantitative measure of ventil3tion efficiency. This in turn led to recommendations for air circulation patterns in rooms. The measured ventilation efficiency enabled energy and CO₂ models to fit measured data. Energy savings of approximately 20% were found for this application. Subjective response of the occupants also was measured. A special questionnaire, subjected to statistical analysis, showed that the subjects felt warmer with increased CO₂ in the room air.     

Validity of detection of microbial growth in buildings by trained dogs

Microbial growth in buildings may evoke respiratory and other symptoms in the occupants and promote decay of construction materials. The decay in wood is usually caused by dry-rot fungus, leading to the decomposition of cellulose and lignin. There are also some mold fungi and bacteria that can use wood as a nutrient. In this study, two trained dogs were used to detect microbial growth present in buildings. The rot fungi Serpula lacrymans, Coniophora puteana and Antrodia sinuosa were used in the training. In addition to decay samples, pieces of healthy birch, pine and imbued wood were used as controls. Another experiment was made using bacteria (Streptomyces sp.). In these experiments, a total of 100 decay, 75 control and 25 bacteria samples were used. The dogs detected 75% of the decay and 60% of the bacteria samples. Some (0-24%) control samples were also expressed as positive. Since the dogs identified also the bacteria samples without any specific training, a new test with some mold strains (Cladosporium, Botrytis, Trichoderma, Penicillium, Aspergillus) was carried out. The dogs found all the decay, mold and bacteria samples but only one sample of healthy wood. The use of dogs to detect mold or decay damage appears to have high specificity and high positive predictive value, but low sensitivity.     

Efficient ventilation in office rooms

Results from a two-box model for calculation of tracer gas concentrations in rooms are given and consequences of different definitions of “ventilation efficiency” are discussed. Results from three different series of experiments are presented. The first two series were dilution experiments; examples of the results are given and discussed. The third series of tests was performed with one person working at a desk in the test room. Above the person;s head, a tracer gas (N₂O) was injected into the convection plume, with as low momentum as possible. Starting with zero concentration, a test continued until steady-state conditions were established for the concentration levels in the different parts of the room. The tests included simulation of summer, autumn/spring, and winter daytime conditions. The results indicate a tendency towards lower tracer gas concentrations in the “breathing zone” when the supply air (typical flow rate equivalent to two air changes per hour) is brought into the room at a low level as compared to a high level close to the ceiling. The exhaust air terminal device in all tests was situated high in the “corridor” wall.     

Formaldehyde in indoor air: Sources and toxicity

Formaldehyde, a highly reactive gas with a pungent odor, is released from a variety of sources including urea-formaldehyde foam insulation, particle board, and plywood, as well as various combustion processes. Concentrations of formaldehyde associated with the presence of these products are higher indoors than outdoors. Under controlled conditions, formaldehyde causes eye and nasal irritation at air concentrations of 0.24 mg/m³ and above. Exposure, residential or occupational, has been associated with eye, nose, and throat irritation, coughing, wheezing, skin rashes, nausea, and other symptoms. Formaldehyde is also a sensitizer; Individuals who are allergic to formaldehyde, or who suffer from respiratory diseases, are likely to suffer the effects of formaldehyde at even lower concentrations. Based on its known metabolism, reactivity with DNA and other marcomolecules, as well as its mutagenic effects in many test systems, formaldehyde is thought to be genotoxic. Recent studies have indicated that formaldehyde is also a carcinogen in rats and probably in mice. Epidemiological studies to date have been inadequate to determine whether or not formaldehyde is a human carcinogen. Formaldehyde seems to be a direct acting carcinogen and it is likely to pose a carcinogenic risk to humans.     

Within-room and within-building temporal and spatial variations in concentrations of polybrominated diphenyl ethers (PBDEs) in indoor dust

Within-house and within-room spatial temporal variability in PBDE contamination of indoor dust may influence substantially the reliability of human exposure assessments based on single point samples, but have hitherto been little studied. This paper reports concentrations of PBDEs 17, 28, 47, 49, 66, 85, 99, 100, 153, and 154 in indoor dust samples (n = 112) from two houses in Birmingham, UK. To evaluate within-house spatial variability, four separate rooms were sampled in house 1 and two separate rooms sampled in house 2. Up to four different 1 m² areas in the same room were sampled to evaluate within-room spatial variability, and for all studied areas, samples were taken for eight consecutive months to evaluate temporal and seasonal variability. Concentrations of ΣPBDEs in individual samples from house 1 varied between 21 and 280 ng g^− 1; while the range of concentrations in house 2 was 20–1000 ng g^− 1. This indicates that where and when a sample is taken in a house can influence substantially the contamination detected. In one room, concentrations of PBDEs in an area located close to putative PBDE sources exceeded substantially those in an area 2 m away, with marked differences also observed between two areas in another room. Substantial within-room spatial differences in PBDE concentrations were not discernible in the other rooms studied. Concentrations of PBDEs in the majority of rooms within the same houses were not markedly different between rooms. Nevertheless, large differences were observed between PBDE concentrations detected in two rooms in the same house in both houses studied. In one instance, this is hypothesised to be attributable to the presence of a carpet in one room and bare wooden floor in another, but firm conclusions cannot be drawn. Within-room temporal (month-to-month) variability was substantial (relative standard deviations for ΣPBDEs = 15–200%). In some rooms, the introduction and removal of putative sources like a TV and a bed, appeared to exert a discernible influence on PBDE concentrations. PBDE concentrations in spring and summer were not markedly different from those observed in autumn and winter. Possible dilution of PBDE concentrations in dust at higher dust loadings (g dust per m² floor surface) was investigated in a small number of rooms, but no firm evidence of such dilution was evident.     

A pilot survey of blood lead levels in various types of workers in the United Arab Emirates.

The aim of the present study is to determine the effect of blood lead on the health of industrial workers in United Arab Emirates (UAE). This is a cross-sectional pilot survey of blood lead levels (BLL) of 100 industrial workers (exposed) and 100 non-industrial workers (nonexposed), matched for age, sex and nationality selected from Al-Ain, Abu-Dhabi Emirate. Industrial workers had significantly higher mean of BLL (77.5+/-42.8 microg/dl and median 80.9 microg/dl) than non-industrial workers (19.8+/-12.3 microg/dl and median 11.0 microg/dl). In the present study, reported symptoms among industrial workers were strongly associated with BLL nausea/vomiting, muscular symptoms, dizziness, fatigue, irritability, memory disturbances, insomnia and allergic conjuctivitis, rhinitis and dermatitis. Furthermore, the present study revealed that industrial workers had higher prevalence of respiratory symptoms for phlegm, shortness of breath and diagnosed asthma. In conclusion, this study determined that occurrence of certain symptoms might be associated with lead exposure among industrial workers.     

Increased incidence of allergic rhinitis,bronchitis and asthma,in children living near a petrochemical complex with SO2 pollution

This study aims to investigate incidence of allergic rhinitis, bronchitis and asthma, in children living near a petrochemical complex with SO₂ pollution obtained by air monitoring stations. A total of 587 children aged 11 to 14 were recruited and classified into high and low exposure groups based on a radius of 10 km from the complex. To study the influence of health on children since the operation of complex in 1999 and observe the difference of these diseases' short-term and long-term impact, we obtained the incidence rates of allergic rhinitis (ICD-9: 477), bronchitis (490–491) and asthma (493) from the Taiwan Health Insurance Database for three periods: 1999–2002, 1999–2006, and 1999–2010. Since 2001, the mean and 99th percentile of SO₂ concentrations in the high exposure area have been significantly higher than those in low exposure area. There were significant differences between the high and low exposure groups in the percentage of smoking, alcohol consumption, passive smoking exposure and incense burning habits. The incidence rates of three intervals were 26.9%, 35.7%, 41.7%; 8.3%, 8.8%, 10.2%; 18.5%, 25.0%, 26.9% for allergic rhinitis, bronchitis and asthma in high exposure group. Significant differences were found between groups for allergic rhinitis in all periods, bronchitis in the first two periods, and asthma in the first period using Student's t-test. After we adjusted age, gender, group, living near roads, incense burning and passive smoking exposure, the hazard ratios between exposure groups were 3.05, 2.74, and 1.93 for allergic rhinitis with significant difference in three periods, and 2.53, 1.92 and 1.72 for bronchitis with significant difference in first period and 1.60, 1.28 and 1.29 for asthma with significant difference in first period by Cox regression. The higher incidence of allergic rhinitis was related to boys and living near roads and the higher incidence of asthma was also related to younger children, boys, and passive smoking exposure.