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Background: Total paper dust exposure has been associated with respiratory problems among workers in the soft tissue paper industry. However, a comprehensive job exposure matrix (JEM) has not been developed for application to this industry. Our study was intended to address this need and to support further studies of mortality and morbidity in a cohort of Swedish workers from this industry., Methods: We evaluated four participating soft tissue paper mills in Sweden. We combined information on process and equipment status from the mills with knowledge of the mills obtained through research efforts and paper dust measurements made at all four mills to develop a semi-quantitative JEM with seven dust exposure levels. The JEM was targeted at workers enrolled into a soft tissue paper mill cohort and working any time between 1960 and 2009., Results: The JEM includes a total of 14 421 cells, with each cell corresponding to the exposure for a job title, department, or work location for a one-year period. Exposure levels in the JEM were estimated to decline at three of the four mills from 1971 to 2009, but overexposures (ie, exceedances of the relevant occupational exposure limits) remained common at the end of the period., Conclusions: The JEM results highlight the need for ongoing exposure control efforts in the soft tissue paper industry, and will inform ongoing epidemiological studies of the health effects of exposure to paper dust in Sweden. It is freely available for use by other researchers., (© 2020 Wiley Periodicals, Inc.)

Purpose: To study respiratory effects of exposure to soft paper dust exposure, a relationship that is rarely studied., Methods: Soft tissue paper mill workers at a Swedish paper mill were investigated using a questionnaire and lung function and atopy screening. Spirometry without bronchodilation was performed with a dry wedge spirometer, and forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV 1 ) were obtained and expressed as percent predicted. Exposure to soft paper dust was assessed from historical stationary and personal measurements of total dust, in addition to historical information about the work, department, and production. The impact of high exposure to soft paper dust (> 5 mg/m 3 ) vs. lower exposure ≤ 5 mg/m 3 , as well as cumulative exposure, was analyzed using multiple linear regression models. Multivariate models were adjusted for smoking, atopy, gender, and body mass index., Results: One hundred ninety-eight current workers (124 male and 74 female) were included. There were significant associations between both cumulative exposure and years of high exposure to soft paper dust and impaired lung function. Each year of high exposure to soft paper dust was associated with a 0.87% decrease in FEV 1 [95% confidence interval (CI) - 1.39 to - 0.35] and decreased FVC (- 0.54%, 95% CI - 1.00 to - 0.08) compared to the lower exposed workers., Conclusions: The present study shows that occupational exposure to soft paper dust (years exceeding 5 mg/m 3 total dust) is associated with lung function impairment and increased prevalence of obstructive lung function impairment.

Objectives: Occupational exposure to soft paper dust is associated with impaired lung function. Whether there is an increased risk for asthma or chronic obstructive pulmonary disease (COPD) is unclear., Methods: We studied 7870 workers from three Swedish soft paper mills, and defined high-exposed workers, as having been exposed to soft paper dust exceeding 5 mg/m 3 for at least 5 years. The remaining workers were classified as 'low exposed'. Person-years at risk were calculated and stratified according to gender, age and calendar-year. The follow-up time was from 1960 to 2013. The expected numbers of deaths were calculated using the Swedish population as reference and standardised mortality ratios (SMRs) with 95% CIs were assessed., Results: There was an increased mortality due to obstructive lung disease (asthma and COPD), among high-exposed workers, SMR 1.89, 95% CI 1.20 to 2.83, based on 23 observed cases. High-exposed workers had an increased mortality from asthma, SMR 4.13, 95% CI 1.78 to 8.14, based on eight observed cases. The increased asthma mortality was also observed among high-exposed men, SMR 4.38, 95% CI 1.42 to 10.2, based on five observed cases. The asthma mortality among low-exposed workers, both men and women, was not increased. The COPD mortality was not clearly increased among high-exposed workers (SMR 1.52, 95% CI 0.85 to 2.50)., Conclusion: High occupational exposure to soft paper dust increases the mortality due to asthma, and the results suggest that soft paper dust levels in workplaces should be below 5 mg/m 3 ., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2020. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: The primary aim of the present study was to investigate if exposure to dust from absorbent hygiene products containing superabsorbent polymer is related to symptoms from the airways and from the eyes. The secondary aim was to estimate the current exposure to superabsorbent polymer among production and maintenance workers in a plant producing hygiene products., Methods: The cohort comprised 1043 workers of whom 689 were exposed to super absorbent polymer and 804 were exposed to paper dust (overlapping groups). There was 186 workers not exposed to either superabsorbent polymer or to paper dust They were investigated with a comprehensive questionnaire about exposure, asthma, rhinitis and symptoms from eyes and airways. The results were analyzed with logistic regression models adjusting for sex, age, atopy and smoking habits. An aerosol sampler equipped with a polytetrafluoroethylene filter with 1 μm pore size was used for personal samplings in order to measure inhalable dust and superabsorbent polymer., Results: The prevalence of nasal crusts (OR 1.4, 95% CI 1.01-2.0) and nose-bleeding (OR 1.7, 95% CI 1.2-2.4) was increased among the paper dust exposed workers (adjusted for superabsorbent polymer exposure). There were no significant effects associated with exposure to superabsorbent polymer (adjusted for paper dust exposure). The average exposure to inhalable levels of total dust (paper dust) varied between 0.40 and 1.37 mg/m³. For superabsorbent polymer dust the average exposure varied between 0.02 and 0.81 mg/m³., Conclusions: In conclusion, our study shows that workers manufacturing diapers in the hygiene industry have an increased prevalence of symptoms from the nose, especially nose-bleeding. There was no relation between exposure to superabsorbent polymer and symptoms from eyes, nose or respiratory tract, but exposure to paper dust was associated with nose-bleeding and nasal crusts. This group of workers had also a considerable exposure to superabsorbent polymer dust.

Objectives: To clarify whether occupational exposure to paper-dust is associated with an increased risk of non-infectious rhinitis., Methods: Thirty-seven workers exposed to paper-dust in a soft-paper mill were compared with 36 unexposed controls. The study was performed under normal working conditions during the non-pollen season. Medical and occupational history was taken down in a comprehensive questionnaire and nasal symptoms were scored on a visual analogue scale (VAS). Pulmonary and nasal function was assessed by spirometry, acoustic rhinometry and peak nasal inspiratory flow. Nasal lavage was analysed for interleukin-8 (IL-8) and nasal transit time was monitored with the saccharine test. Concentrations of inhalable dust for each exposed subject during the day of the clinical study were measured with personal sampling devices., Results: There was an increased prevalence of nasal blockage and crust formation among the exposed workers. However, there was no difference with regard to acoustic rhinometry, nasal transit time or nasal peak inspiratory flow. In the whole population, IL-8 in nasal lavage was higher among men than among women, 193 ng/l vs 132 ng/l, P = 0.006. There was also a positive trend (P = 0.01) with increasing nasal IL-8 going from non-smokers (122 ng/l), ex-smokers (126 ng/l) to current smokers (235 ng/l)., Conclusions: We have found that occupational exposure to paper-dust is associated with symptoms of nasal blockage and nasal crusting. We find no objective signs of nasal inflammation, even among the subgroup with the highest current exposure.

The aim of the present cross-sectional study was to investigate whether long-term exposure to soft paper dust causes impairment of lung function. Exposed workers (n = 287) and referents (n = 79) were investigated, using spirometry and questionnaires. Personal samplings of total dust showed that the actual mean concentrations did not exceed 3 mg/m3. The exposed subjects were divided into three categories according to historical and present exposure to paper dust; low exposure, moderate exposure and high exposure. The study did not show any lung function impairment due to exposure to paper dust. However, the exposed subjects had a significantly increased prevalence of symptoms from both the upper and lower airways as well as an increased prevalence of reported asthma. On the basis of our study, we conclude that lung function impairment does not occur among workers exposed to mean levels of soft paper dust below 5 mg/m3.

Objectives Paper dust has previously been linked to adverse health effects. However, a comprehensive dataset of paper dust exposures does not appear to have been published previously. Our study was intended to address this need by describing a large dataset of measurements made in Swedish soft tissue paper mills. Methods We compiled personal and area total dust exposure measurements collected from a range of operations by our research staff at four soft tissue paper mills in Sweden. We also compiled measurements made by the occupational health staff at each mill and the Swedish Work Environment Authority. We analyzed these measurements to describe patterns and trends in exposures and used mixed-effects regression models to identify measurement characteristics that predicted exposure levels. Results We compiled 1578 measurements from 1971 to 2009, of which 1026 (65%) were personal samples. Statistically significant differences were found between measurements made by research, mill, and Swedish Work Environment Authority staff, as well as between personal and area measurements. The measurement data suggest that, beginning in the 1980s, exposures declined at three of the four mills, but that overexposures were still common at the end of the period. Papermaking and converting operations had the highest observed dust exposures. One mill had significantly lower exposures than the others. Type of measurement (personal versus area) and source of measurement (research staff, company, or regulatory agency) were not significant predictors of measured total dust exposure after controlling for mill, operation, and time. Conclusions Our analysis of measured paper dust exposures may be useful for historical and contemporary exposure assessment in our own and other epidemiological studies. We have identified specific characteristics (i.e. papermaking operations and mill) and time trends that are important data features to consider, and documented continuing overexposure situations. Our results highlight the ongoing need for application of exposure controls to reduce paper dust exposures in the soft tissue paper industry. [ABSTRACT FROM AUTHOR]

Background: Some largely inconsistent associations between parental occupational dust exposure and childhood cancer have been reported, with maternal exposures inadequately studied. The authors examined whether maternal or paternal occupational exposure to animal, wood, textile, or paper dust around a child's birth was associated with an increased risk of childhood cancer, both overall and by type (leukemias, lymphomas, central nervous system tumors, and other cancers). Methods: In this nationwide, register‐based, case‐control study, children who were diagnosed with cancer from 1960 to 2015 were compared with up to 25 matched controls regarding maternal and paternal occupational dust exposure (9653 cases in maternal analyses and 12,521 cases in paternal analyses). Exposures were assessed using a job‐exposure matrix and occupational information from census and register data. By using conditional logistic regression models, adjusted odds ratios (ORs) and 95% confidence intervals (CIs) were estimated. Results: Neither maternal nor paternal occupational exposure to animal, wood, textile, or paper dust was associated with childhood cancer overall, leukemias, or central nervous system tumors. Maternal, but not paternal, wood dust exposure was associated with an increased risk of lymphoma (OR, 1.42; 95% CI, 1.10‐1.84), particularly non‐Hodgkin lymphoma (OR, 2.03; 95% CI, 1.21‐3.40). Conclusions: The current study did not confirm the associations reported previously but is the first to suggest a link between maternal occupational exposure to wood dust around pregnancy and lymphoma in the offspring. This large study does not confirm associations reported previously for leukemia and central nervous system tumors but is the first to suggest a link between maternal occupational exposure to wood dust around pregnancy and lymphoma in the offspring. [ABSTRACT FROM AUTHOR]

Objectives: We estimated the association between occupational exposures to five different organic dusts: wood, animal, paper, textile and flour dust and the risk of developing rheumatoid arthritis (RA)., Methods: This population-based case-control study analysed 12 582 incident cases and 129 335 controls. Participants were identified from national public authority and quality registers. Census data on occupations were collected 1960-2010 and we estimated the exposure to organic dust with the help of job-exposure matrices. We used logistic regression to assess the OR of seropositive or seronegative RA. Estimates were adjusted for the matching variables (sex, county, age and index year), education and occupational silica exposure., Results: Exposure to animal dust was associated with an increased risk of RA among both men and women. The OR was 1.2 (95% CI=1.1 to 1.4) for seropositive RA and 1.3 (95% CI=1.1 to 1.5) for seronegative RA among ever exposed participants compared with unexposed. The risk increased with duration of exposure for seropositive RA, and participants who had been exposed in five or more censuses had an OR of 1.6 (95% CI=1.1 to 2.2, p for trend=0.003). Exposure to textile dust also generated a significant dose-response relationship for seropositive RA (p for trend=0.014). We detected no association between exposure to wood, paper or flour dust and risk of RA., Conclusions: Overall, exposure to animal dust and textile dust was associated with an increased risk of developing RA. These observations give further support to the notion that airborne exposures are involved in the aetiology of RA., Competing Interests: Competing interests: LA have for the EIRA study been supported by research grants from the Swedish Medical Research Council; the Swedish Council for Health, Working Life and Welfare; King Gustaf V:s 80-year foundation; the Swedish Rheumatism Foundation; Stockholm County Council; the insurance company AFA Insurance and the IMI-supported RTCure projects, unrelated to the submitted work. PW has received research grants from AFA Insurance, unrelated to the submitted work. PG has received research grants from the Swedish Research Council for Health, Working Life and Welfare, unrelated to the submitted work. LA received grants from the Swedish Research Council for Health, Working Life and Welfare (grant no: 2013-0194) and AFA Insurance (grant number 120299) to support the present study., (© Author(s) (or their employer(s)) 2019. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

An experimentally based prediction model of road abrasion wear due to studded tyres is available in Sweden and has been found to work well. However, it has not been validated since 2007, and since then road surfaces and tyre design have developed, and the question has arisen regarding the model's current validity. The abrasion wear model is used in the NORTRIP emission model (NOn-exhaust Road Traffic Induced Particle emission modelling), and the effect of a recalibrated abrasion wear model on the emission model is shown. In this paper, the abrasion wear model is compared to full-scale field measurements at several recently constructed roads in Sweden to investigate its validity, while also proposing changes to allow for continued use. It is concluded that the model overestimates the wear and an update is suggested. In addition, the impact on NORTRIP emission predictions is briefly investigated. There were also indications that NORTRIP is affected by the abrasion model overestimating the contribution of pavement wear to the particle emissions. [ABSTRACT FROM AUTHOR]

The clinical significance of this paper is the statistically increased mortality and morbidity on respiratory diseases in outpatients of Swedish foundry workers, particularly COPD, at certain exposure levels. The results can be used as risk assessment for individuals to prevent the development of respiratory diseases and as basis for new occupational exposure limits. Objective: The mortality and morbidity pattern for respiratory diseases was determined in a cohort of 1752 Swedish foundry workers, particularly for respirable silica dust exposure. Methods: The morbidity follow-up in the Swedish National Non-primary Outpatient Register covered 2001 to 2017 (NPR; specialist not in care patients), the mortality from the National Causes of Death Register covered 2001 to 2017. Cumulative exposures to silica and dust were determined. Results: The morbidity in COPD showed significantly increased risk for all exposure groups, as did silicosis in the high exposure group, these cases corresponded to silica exposure levels below 0.05 mg/m3. The mortality of all causes and respiratory diseases was significantly increased by cumulative silica exposure in the high exposure group. Conclusions: Significantly increased morbidity for respiratory diseases and COPD was determined at silica exposure levels below the current Swedish OEL. [ABSTRACT FROM AUTHOR]

Objective: Ambient particle matter is a risk factor for cardiovascular disease (CVD). However, little is known about associations between particles in occupational settings and risk of CVD. We investigated associations between occupational dust exposure and biomarkers of CVD, and potential recovery effects after vacation. Methods: Personal dust exposure measurements (respirable silica, respirable dust < 4 µm, and particles of 0.1–10 µm (PM 0.1–10) were conducted once, and biological sampling were performed twice on non-smoking, male construction workers in Stockholm county, Sweden; during work and immediately after summer vacation. Linear regressions with adjustments for confounders and covariates were performed evaluating associations between occupational dust exposure and biomarkers. Paired t tests were performed evaluating changes before and after vacation. Results: Sixty-five workers participated. Homocysteine concentrations were significantly higher with increasing concentrations (mg/m3) of respirable silica, respirable dust, and PM 0.1–10, and pulse rate with higher levels of respirable dust and dust of PM 0.1–10. Homocysteine levels were also positively correlated to number of years of dust exposure, as were low-density lipoprotein (LDL) levels. A clear recovery effect was present for LDL after vacation, but not for homocysteine. Conclusions: Occupational dust exposure was associated with some CVD risk markers, even at mean exposure concentrations below the Swedish occupational exposure limits for respirable silica and respirable dust, respectively. Vacation resulted in recovery for some risk markers. However, the change of the homocysteine and LDL levels suggest a long-term effect. Reduction of occupational exposure to dust may decrease the risk of CVD among exposed workers. [ABSTRACT FROM AUTHOR]

Abstract: The aim of this paper is to contribute to the discussion on how satisfaction with different aspects of indoor environment contributes to occupants'' overall satisfaction. The analysis is based on survey responses collected during a unique project commissioned by The Swedish National Board of Housing, Building and Planning. The results are representative of adults living in multi-family buildings in Sweden. The analysis shows that generally satisfaction with air quality has the highest impact on occupants'' overall satisfaction. The occurrence of problems with indoor environment quality, particularly draught, dust and too low indoor temperature may affect occupants'' overall satisfaction. However, it is demonstrated that the importance impact of perceived indoor environment quality on overall satisfaction is affected by individual and building characteristics. [Copyright &y& Elsevier]

We present a high-resolution peat paleodust and accumulation rate record spanning the last 8300 years from Draftinge Mosse (400 ha), southern Sweden (57°06′27.6"N 13°42′54.1″E). The record was analysed for peat accumulation rates (PAR), elemental concentrations, mineralogy, and plant macrofossil content. Five periods of increased mineral deposition were recorded. The first event occurred between ~6280 and ~5570 cal BP, during the fen to bog transition. This is followed by four atmospheric mineral dust events (DE) which were recorded in the ombrotrophic section of the sequence at (cal BP): ~2200; ~1385–1150; ~830–590, and from ~420 to the present. Statistical analysis and elemental ratios indicated that both the mineralogy and grain size shifted when the system transitioned from fen into bog, showing that the governing transport process shifted with the peatland succession stages. This highlights the importance of identifying peatland succession stages within peat paleodust studies. Following all four DE, increases in PAR were observed, implying a coupling to dust deposition. Comparison of DE and PAR with a paleodust record from Store Mosse, a 20 times larger bog located ca 18 km away (Kylander et al. 2016), showed that both PAR and dust deposition are largely represented by single-core reconstructions, indicating that they are driven by a common climate forcing mechanism. However, higher PAR and dust deposition rates were observed in the more moderately sized Draftinge Mosse, suggesting that the size of the bog is important to consider in peat paleodust studies. Furthermore, the smaller bog responded more rapidly to hydrological changes, indicating that the size of the bog affects its' buffering capacity. Authigenic carbonates, observed here during episodes of rapid peat growth, coincide with changes in REE ratios, indicating that authigenic peat processes potentially cause REE fractionation. • This paper presents a high resolution peat paleodust and growth rate record. • Comparison with a nearby paleodust site showed similarities, indicating a common forcing mechanism. • Differences in recorded dust intensities indicate that the size of the bog matter. • The peatland development is important for assessing mineral transport processes. • Authigenic carbonates affected REE ratios. [ABSTRACT FROM AUTHOR]

As the dust of society-wide digitalisation settles, the search for meaningful technological encounters is becoming more urgent. While the Nordic countries embrace digitalisation, recent concerns regarding technology overuse have been gaining increased attention. This tendency is exemplified in practices of limiting digital use, called digital disengagement -- an apparent paradox in Nordic societies where digital is the dominant paradigm. In this article, we explore the emergence of disconnection-centred devices called "dumbphones", which cater to individuals wishing to escape hyperconnected lifestyles. Drawing on a new materialist perspective, we present a content analysis of dumbphones' advertising material, followed by a collaborative autoethnographic study in which we replace our smartphones with dumbphones. We critically weigh the promises of the dumbphones against the actual experience of digital disengagement in Sweden. Our findings illustrate a struggle with digital technologies, even despite their absence, due to emerging workarounds and societal expectations of use. [ABSTRACT FROM AUTHOR]

Resuspension of road dust contributes to air quality issues with resulting health impacts. Limited studies imply that porous pavements can initially mitigate PM10 emissions by acting as a dust trap, but the abrasion wear generates road dust and thus accelerates the clogging processes. In addition, knowledge regarding the impact of pavement types on road dust load dynamics is limited. Road traffic noise can be mitigated using porous pavements, but the use of studded tyres increases the abrasion wear of the pavement as well as increasing the noise emission. Due to this durability problem, porous pavements are rarely used in the Nordic countries where, instead, dense pavements which are abrasion resistant are more common. Linköping municipality, in Sweden, constructed a porous pavement to mitigate road traffic noise. This led to the opportunity to investigate the temporal variation of the dust load dynamics and inherent size distributions over the winter and spring in comparison to those of an adjacent dense pavement. Results, when using the wet dust sampler (WDS) method, showed similar dust load dynamics for the dense and porous pavements. The results were also compared to previous studies using the same method on different dense pavements in Stockholm, Sweden. All locations showed a seasonal variation with higher dust loads during winter and early spring and declining loads towards summer. The size distributions were more complex for the wheel tracks at the porous pavement, having primarily properties of a mixture model compared to the simple size distributions for the dense pavement. On the other hand, the dust load and size distribution were more similar between the porous and dense pavements regarding loads and shapes, indicating a less pronounced but similar behaviour between the surfaces outside of the wheel tracks. [ABSTRACT FROM AUTHOR]

Background: Particle exposure is a risk factor for cardiovascular diseases. Mitochondrial DNA (mtDNA) is a primary target for oxidative stress generated by particle exposure. We aimed to elucidate the effects of occupational exposure to particle-containing welding fumes on different biomarkers of mtDNA function, and in turn, explore if they modify the association between particle exposure and cardiovascular response, measured as blood pressure.Methods: We investigated 101 welders and 127 controls (all non-smoking males) from southern Sweden. Personal sampling of the welders' exposure to respirable dust was performed during work hours (average sampling time: 6.8 h; range: 2.4-8.6 h) and blood pressure was measured once for each subject. We measured relative mtDNA copy number by quantitative PCR and methylation of the mitochondrial regulatory region D-loop and the tRNA encoding gene MT-TF by bisulfite-pyrosequencing. We calculated the relative number of unmethylated D-loop and MT-TF as markers of mtDNA function to explore the modification of mtDNA on the association between particle exposure and blood pressure. General linear models were used for statistical analyses.Results: Welders had higher mtDNA copy number (β = 0.11, p = 0.003) and lower DNA methylation of D-loop (β = -1.4, p = 0.002) and MT-TF (β = -1.5, p = 0.004) than controls. Higher mtDNA copy number was weakly associated with higher personal respirable dust exposure among welders with exposure level above 0.7 mg/m3 (β = 0.037, p = 0.054). MtDNA function modified the effect of welding fumes on blood pressure: welders with low mtDNA function had higher blood pressure than controls, while no such difference was found in the group with high mtDNA function.Conclusion: Increased mtDNA copy number and decreased D-loop and MT-TF methylation were associated with particle-containing welding fumes exposure, indicating exposure-related oxidative stress. The modification of mtDNA function on exposure-associated increase in blood pressure may represent a mitochondria-environment interaction. [ABSTRACT FROM AUTHOR]

A clean-up method was developed to enable the determination of tri-decabrominated diphenyl ethers, isomer-specific hexabromocyclododecanes (HBCDs), 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE), decabromodiphenyl ethane (DBDPE), (2-ethylhexyl)tetrabromobenzoate (TBB), and bis(2-ethylhexyl)tetrabromophthalate (TBPH) in the same dust sample extract using reasonable amounts of solvents and without dividing the sample. After extraction, the sample was separated on a silica column into three fractions that were subsequently cleaned up individually. The polybrominated diphenyl ethers (PBDEs) and DBDPE were eluted in Fraction I, TBB, TBPH, and BTBPE in Fraction II, and HBCDs in Fraction III. Fractions I and II were analyzed using gas chromatography/mass spectrometry and Fraction III using liquid chromatography/mass spectrometry. The method gave good recoveries (60-120%), precise results using C-labelled internal standards and was accurate when comparing results to certified values (PBDEs in NIST SRM 2585). The method was applied to dust samples from the Stockholm (Sweden) area. All the emerging brominated flame retardants (BFRs) studied, except BTBPE, were present in all the samples in quantifiable concentrations, often higher than the PBDEs. BTBPE was quantified in only one sample. It is evident that emerging BFRs are present in Swedish homes, and these compounds should be included in the BFR analyses of indoor environments. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

Dust suppressants were applied on fifteen 1 km long test sections at four sites in Sweden during three summer seasons with the objective to compare their relative efficiency and determine minimum application rates in Nordic climate. Dust generation from the test sections was measured both visually and by PM10 measurements. All products except lignosulphonate, sugar and bitumen emulsion showed acceptable efficiency. Chloride solutions were the most efficient. Results indicate the possibility to reduce application rates of chlorides by applying them as solutions instead of solids. The minimum application rate for a chloride solution was estimated at 0.8 m3/km, which is equivalent to a rate reduction of 50% by weight compared with traditionally applied rates of solid chloride. The results are expected to reduce life cycle costs for gravel roads and contribute to environmental gains by reducing the release of dust into the atmosphere and chemicals into the environment. [ABSTRACT FROM AUTHOR]

We investigated the levels of mite (Der p I and Der f I) allergen in dust from bedrooms, living rooms, kitchens, and bathrooms from 130 homes of asthmatic children in three climatic zones of Sweden. Bedroom dust samples included the child's mattress, carpets, floors, and other plain surfaces. Living-room dust samples were taken from sofas and Other furniture, carpets, floors, and other plain surfaces. The allergen levels were related to home characteristics, including absolute indoor humidity (AIH), relative humidity (RH), and air changes per hour (ach). Mite allergen was detected in 62% of the homes. Levels of Der p I varied between <16 ng and 50 μg/g dust, and Der f I between.. <16 ng and 73 μg/g dust. Because we have designed a composite type of dust collection in our study, the allergen levels found tend to average down the results. Mite allergen levels were higher in homes with dampness problems, in homes with a smoker, and in homes without a basement Homes with high absolute humidity (≥ 7 g/kg) or relative humidity (> 45%) and poor ventilation (<0.5 ach) contained higher levels of mite allergens than homes, with lower humidity and better ventilation, However, the number of ach measurements in homes was not high, and few homes had > 0.5 ach. Sensitization to house-dust mites was more common in southern than in northern and central Sweden. "High levels of house-dust mite allergen in a temperate. climate where mites are not ubiquitous are thus associated with dampness problems in homes and with tobacco smoking. Our data confirm and extend previous findings that high AIH and RH and poor ventilation increase the risk of mite infestation in homes. It seems to be important and necessary to control indoor humidity and ventilation levels, to avoid high mite allergen exposure in a temnperate climate, because 34% of mite-sensitized asthmatic children were exposed to levels of mite allergen <2 μg/g dust in their homes. The study also shows that mite allergen levels below the suggested threshold level (2 μg/g dust) are associated with mite sensitivity in children with perennial symptoms of asthma. [ABSTRACT FROM AUTHOR]