Positive impact on vitamin D related lifestyle of medical advice in pregnant Somali-born women and new mothers: a mixed method study in Swedish primary care.

BACKGROUND: A previous study showed that pregnant women/new mothers especially Somali-born and some Swedish-born had extremely low vitamin D levels and poor physical performance. Our study aimed to examine vitamin D related lifestyle, attitudes and behaviour before and after brief information about vitamin D, with special long-term focus on Somali-born women. METHODS: A cohort of 91 pregnant women/new mothers having serum hydroxyvitamin D (S-25-OHD) ≤ 50 nmol/L (n = 51 Somali-born with one third < 10 nmol/L of S-25-OHD) in primary health care in Sweden was targeted for intervention. Brief individual oral and visual information on vitamin D was given by doctors at baseline and after four and ten months. Questionnaires with ordinal scales on vitamin D related lifestyle of food, clothing, and outdoor activities were distributed on all occasions. Focus-group interviews with 15 women from the target-group were performed after two years. A Somali interpreter was available. RESULTS: Veiled clothing, indoor living, and a low intake of milk, cheese, and fatty fish were common in the target group. Consumption pattern had increased significantly among the Somali-born women at the four-month follow-up but declined to non-significant levels at the ten-month follow-up. The focus-group interviews showed improved understanding of vitamin D deficiency, symptoms and attitudes, but varying applied behaviours related to sun exposure. Sun exposure for the children and increased fish consumption was the most evident positive results. CONCLUSIONS: Vitamin D related lifestyle, attitudes and behaviour improved in a Somali-born group of pregnant women/new mothers with severe vitamin D deficiency. The preventive measures suggested in our study may have impact on public health in relation to bone and muscle strength and immunity especially in vitamin D deficiency risk groups. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02922803 . Date of registration: 28 September 2016.

Comparison of VOC and ammonia emissions from individual PVC materials, adhesives and from complete structures.

Emission rates of volatile organic compounds (VOCs) and ammonia measured from six PVC materials and four adhesives in the laboratory were compared to the emission rates measured on site from complete structures. Significantly higher specific emission rates (SERs) were generally measured from the complete structures than from individual materials. There were large differences between different PVC materials in their permeability for VOCs originating from the underlying structure. Glycol ethers and esters from adhesives used in the installation contributed to the emissions from the PVC covered structure. Emissions of 2-ethylhexanol and TXIB (2,2,4-trimethyl-1,3-pentanediol diisobutyrate) were common. High ammonia SERs were measured from single adhesives but their contribution to the emissions from the complete structure did not appear as obvious as for VOCs. The results indicate that three factors affected the VOC emissions from the PVC flooring on a structure: 1) the permeability of the PVC product for VOCs, 2) the VOC emission from the adhesive used, and 3) the VOC emission from the backside of the PVC product.

Ergosterol content in various fungal species and biocontaminated building materials

This paper reports the ergosterol content for microbial cultures of six filamentous fungi, three yeast species, and one actinomycete and the ergosterol levels in 40 samples of building materials (wood chip, gypsum board, and glass wool) contaminated by microorganisms. The samples were hydrolyzed in alkaline methanol, and sterols were silylated and analyzed by gas chromatography-mass spectrometry. The average ergosterol content varied widely among the fungal species over the range of 2.6 to 42 &mgr;g/ml of dry mass or 0.00011 to 17 pg/spore or cell. Ergosterol could not be detected in the actinomycete culture. The results for both the fungal cultures and building material samples supported the idea that the ergosterol content reflects the concentration of filamentous fungi but it underestimates the occurrence of yeast cells. The ergosterol content in building material samples ranged from 0.017 to 68 &mgr;g/g of dry mass of material. A good agreement between the ergosterol concentration and viable fungal concentrations was detected in the wood chip (r > 0.66, P 0.48, P 0.63, P < 0.0001). In conclusion, the ergosterol concentration could be a suitable marker for estimation of fungal concentrations in contaminated building materials with certain reservations, including the underestimation of yeast concentrations.

Mutagenic compounds in wood-chip drying fumes.

The mutagenicity of fumes from the heating of freshly cut spruce and birch chips was measured with Salmonella typhimurium strains TA98, TA100 and TA102. The bacteria were exposed directly and indirectly to the fumes. Wood chips were also extracted with solvents. No mutagenicity was found in wood extracts or the fume samples measured indirectly. The results from the direct exposure experiments indicate, however, that drying spruce and birch at 170 degrees C emits mutagenic compounds, which are short-lived and/or volatile. One of the mutagenic compounds of the fumes is probably 3-carene. These results are consistent with previous epidemiological findings, which suggest that these fumes are carcinogenic.

Charcoal sampling method for determining the concentration of styrene in air.

The vapors of styrene (vinylbenzene) were trapped on charcoal in a glass tube. Air from the worker's breathing zone was sucked through the tube by a battery-operated, modified, MSA personal sampling pump. The sampler and pumping system were worn by the worker. The styrene were eluted with dimethyl formamide and estimated by gas chromatography. The range and sensitivity of the method when sampling with a flow rate of 0.2 1/min during 1 h were 5 to 1,500 ppm, and during 4 h they were 2 to 400 ppm. The recovery (accuracy) was over 90%. The precision for the method, in terms of relative standard deviation, was 8.4%.

The tracer gas technique--a useful tool for industrial hygiene.

The tracer gas technique was applied in industrial hygiene surveys. Carbon dioxide, nitrous oxide, and sulfur hexafluoride were used to elicit ventilation rates and determine spreading routes of dilution air in the work environment. The continuous monitoring of nitrous oxide with an infrared spectrophotometer was found to be the most practicable choice for ventilation testing, whereas plastic bag sampling of nitrous oxide or sulfur hexafluoride with subsequent analysis by gas chromatography appeared to be a good method for emission spreading studies. The local flow rates of dilution air and the percentages of make-up air present were the most important information gained in the ventilation studies.

Urinary mandelic acid concentration after occupational exposure to styrene and its use as a biological exposure test.

Excretion of mandelic acid from workers in the reinforced polyester plastic industry was studied with the determination of urinary mandelic acid concentrations. The styrene exposure level at the workplaces was evaluated with measurements of the styrene concentration in the ambient air. Three different groups (I, II and III) were studied. In group I [n=9, median of the time-weighted average (TWA) of exposure = 23 ppmof styrene, postexposure observation period = 64 h] two excretion slopes were observed, the first with a median half-time of 9.4 h (postexposure period 0--18 h) and a second with a median half-time of 16.6 h (postexposure period 19--64 h). For group II (n=9, median TWA exposure = 248 ppm, postexposure observation period = 15 h) a half-time of 6.4 h was found. These results suggest that the excretion rate of mandelic acid is dependent on the styrene exposure level. In addition the mandelic acid concentrations of 29 workers (group III) before and after the work shift were analyzed. The urinary mandelic acid concentrations of groups I, II and III, sampled immediately after the 8-h work shift, correlated with the 8-h TWA of styrene exposure (n=47, r=0.93). Accordingly about 2,300 mg of mandelic acid per gram of creatinine corresponded to 100 ppm of styrene.

Solvent exposure in construction and maintenance painting.

Exposure to solvents in interior house painting was determined by industrial hygiene surveys and questionnaires on work history. Painting work was observed in 92 work situations at 18 sites, mainly during maintenance work. The effects of the size of the work area, the volume of air, the type of paint, the amount used, the method of application, and the use of ventilation on the solvent concentrations were also studied. In small, poorly ventilated rooms the concentration of solvent naphtha averaged 275 ppm when alkyd paints were used. Wall and ceiling painting with alkyd paints yielded an average solvent naphtha concentration of 210 ppm, and window and door painting 80 ppm. The presence of a strong draft reduced the solvent concentrations by two-thirds. The painters' average lifetime dose of solvent naphtha was 12.2 kg, the average annual dose 0.54 kg. These levels decreased over the study period. The mean 8-h concentration of solvent naphtha in the breathing zone averaged 40 ppm over the painters' total worklife.

Chromosome aberrations in peripheral lymphocytes of workers employed in the plywood industry.

Workers employed in sawmills and in the manufacture of plywood are exposed to potentially mutagenic chemical aromatic emissions from wood. However, very little is known about the exposure to these natural wood components. In an attempt to determine whether such exposure could have clastogenic effects, a group of 13 male nonsmoking employees mainly from the beginning of the wood-processing line of three plywood mills and 15 matched nonsmoking referents were studied for chromosome aberrations in blood lymphocytes. A statistically significant elevation of the frequency of cells with chromatid-type breaks (mean 2.1%), as compared with the corresponding frequency of the referents (mean 1.0%), was observed for the lymphocytes of the wood workers. These results lend support to previous studies which suggested that wood-drying fumes may be carcinogenic.

Urinary o-cresol in toluene exposure.

The determination of urinary o-cresol in varying exposure to toluene vapor showed a linear relationship between the metabolite and the inhaled solvent. The analytical method involves acid hydrolysis of 20 ml of urine with subsequent extraction of the phenolic compounds in dichloromethane, followed by gas chromatographic analysis. The lowest limit of detection lies at 0.5 micromol/l, whereas the practical limit as an exposure test is at 2.5 micromol/l [corresponding to 0.2 micromol/l (5 ppm) of toluene vapor]. The test may also have indirect toxicologic significance, as the underlying initial arene oxides which produce the cresolic compounds are involved in toluene toxicity.

Microbial growth on respirator filters from improper storage.

Microbiological contamination and particle penetration were studied in two respirator filters with high efficiency. Microbial growth in filter materials during storage under conditions and the passing of microorganisms through the filters were particularly examined. Filters with different fiberglass and cellulose proportions were loaded in environments containing high microbial levels and incubated at a relative humidity of 98%. Particle penetration through loaded and incubated filters and carbon, nitrogen and microbial content were measured. After incubation, considerable particle penetration and the passing of fungal spores were observed for filters composed mainly of cellulose, probably because of humid conditions, which stimulated fungi to grow and extend mycelia and spores through the filter. Microbial activity, microorganism concentrations, and the chemical properties of the filter materials also supported this hypothesis. Storing used respirators in humid environments may result in heavy microbial contamination of the filters, especially if the filter material is biodegradable by microorganisms.

Indoor radon concentrations caused by construction materials in 23 workplaces.

The aim of this study was to compare the measured and the calculated concentrations of indoor radon caused by building materials at 23 workplaces. The measured concentrations of radon were clearly higher than the calculated radon concentrations from the building materials, which indicated that the main source of indoor radon was the soil under and around the buildings. The highest means of continuously (933 Bq m(-3)) and integrated (169 Bq m(-3)) measured and calculated (from 70 to 169 Bq m(-3)) concentrations of radon were found in hillside locations. On the other hand, the median (27 and 43 Bq m(-3)) and maximum (626 and 1002 Bq m(-3)) values of calculated indoor radon concentrations exhaled from construction materials were the highest at the ground level places. On average, only 7-19% of the radon seemed to originate from the construction materials.

Identification of environmental hazards of gasoline oxygenate tert-amyl methyl ether (TAME).

The physico-chemical and environmental properties of a new gasoline component tert-amyl methyl ether (TAME, 2-methoxy-2-methylbutane) were determined experimentally and environmental hazards of the new component were thereafter identified. The methodology was based on the chemical regulations of the European Union (EU). On the basis of the experimental results, TAME is a volatile, non-hydrophobic and water-soluble liquid, which is not expected to be adsorbed onto organic matter in soil or sediment. It is not readily biodegradable. TAME has very low acute toxicity to aquatic organisms and is not expected to bioaccumulate.

A multi-faceted approach to risk assessment of laboratory animal allergens at two facilities.

BACKGROUND: Risk assessment of exposure to allergens is difficult because the relationship between exposure, sensitization, and symptoms has not been fully established. Laboratory animal allergens (LAA) are an important occupational health risk factor; 10-32% of workers exposed to these allergens develop allergic diseases. This article introduces a versatile approach to assessing the risks posed by LAA at two laboratory animal facilities. METHODS: The risk assessment approach that was used at the laboratory animal facilities included questionnaires for management and employees, a hazard identification visit and measurements in the workplaces, as well as the creation of a list of generally recommended procedures to reduce allergen exposure. RESULTS: The prevalence of work-related allergic symptoms was 17%. Suggested countermeasures at the sites included changes in ventilation and work practices, reduction of unnecessary exposure, recommendations for more comprehensive use of personal protective equipment, and wider communication about LAA risks. CONCLUSIONS: The approach managed to identify critical points and potential means for controlling LAA exposure.

Solvent containing processes and work practices: environmental observations.

Even though there has been a shift toward water-based or fully solid systems, organic solvents still comprise a significant occupational health hazard. Fortunately, exposure levels can nowadays be effectively controlled by proper enclosures and ventilation in most remaining applications of organic solvents, and, generally taken, the development of occupational health conditions has been favorable on the workplaces using organic solvents. When as many as 24.2% of the 2639 solvent measurements carried out by the Institute of Occupational Health in Finland exceeded the occupational health standards between 1971 and 1976, such non-compliance levels were detected only in 3.0% of the 2823 samples taken between 1977 and 1980 (Skyttä, 1978; Kokko, 1982). The persons dealing with occupational health problems in workplaces should also be aware of the possible existence of solvent misuse. This may not develop into the level of solvent sniffing, but into a milder addiction. The workers adopt working habits that cause unnecessary exposure. Repeatedly found exceptionally high concentration levels in biological exposure tests are an indication of a possible abuse.

Estimating long-term exposure levels in process-type industries using production rates.

Exposure to toluene in two publication rotogravure plants was investigated to examine how accurately long-term exposure can be estimated on the basis of production rate. Toluene consumption was used as the measure of production rate. Continuous area monitoring was used to find a correlation between production rate and airborne level of toluene. Workers' exposure levels were first estimated by combining data on toluene concentrations in various monitoring sites with data supplied by the workers on the time spent in these areas. These calculated exposure levels were found to correlate well with the actual exposure levels obtained by breathing zone sampling. There was also a fairly high correlation between the concentration of toluene in front of the press and the consumption of toluene if the process conditions remained stable. It was, however, necessary to investigate this association separately for the situations where the degree of enclosure of the press or number of emission sources were unusual or when the workers stayed in the control rooms, which were separated from the other pressroom areas. A reasonably high correlation between the variables of the main interest, that is, the calculated toluene exposures and the consumption of toluene, was found in one of the plants investigated, whereas this correlation was low in the other plant. Even though this kind of estimation procedure does not always lead to accurate exposure levels, it helps in understanding how those are affected by the process parameters.

Complex chlorinated hydrocarbons: occupational exposure in the sawmill industry.

Exposure to chlorophenols occurs in the vicinity of the lumber treatment area in sawmills and in subsequent work phases where treated lumber is handled. Measurements from several countries indicate that the concentration of chlorophenols in the workroom air is generally below 0.5 mg/m3, the occupational exposure limit of chlorophenols in many countries. Inhalation usually leads to relatively low concentrations of chlorophenols in urine of exposed workers. Frequent skin contact with chlorophenol solution or with freshly treated lumber can produce urine concentrations 10-100 times higher than among those with inhalatory exposure only. In addition to chlorophenols, exposure to toxic polychlorinated dibenzodioxins and dibenzofurans may occur in some tasks carried out in sawmills. Jobs with potentially heavy exposure include the treatment of dipping-vat sludge and processes involving heating of chlorophenols, such as burning of treated waste wood and welding of metal structures contaminated by chlorophenols.

Assessment of total exposure to phenol-formaldehyde resin glue in plywood manufacturing.

OBJECTIVE: Respiratory and dermal exposure to phenol-formaldehyde resin-glue components used in plywood manufacturing were assessed. METHODS: Formaldehyde and phenol were monitored in the workplace air. Formaldehyde was measured both in the breathing zones of the workers and at stationary sampling sites. Phenol was used as a marker agent for dermal exposure due to its near-nonvolatility at the temperatures occurring during the present study and to its ready absorption through the skin, causing systemic exposure in addition to local skin rashes. Sampling and analytical methods were developed to measure the dermal exposure to phenol. Sampling was accomplished with whole-body dosimetry using Tyvek coveralls and cotton gloves. In addition, a liquid chromatography method was developed for the analysis of phenol from dermal exposure samples. RESULTS: As expected, formaldehyde was noted to be the major compound causing respiratory exposure. When exposure assessment was done on the basis of air samples collected both at stationary sampling sites and in the breathing zones of the workers the agreement between the results obtained was good. The dermal sampling revealed that the workers were exposed to phenol, but the risk for toxic effects was slight due to the low concentrations of urinary phenol. CONCLUSIONS: We conclude that it is possible to use the stationary sampling method for the assessment of respiratory exposure in a plywood factory instead of the usually more complicated breathing-zone sampling. This study also demonstrates the importance of taking dermal exposure into account, at least due to the ability of the resins to cause skin rashes, in assessment of the exposure to chemicals in plywood manufacturing.

Exposure to airborne metals in the manufacture and maintenance of hard metal and stellite blades.

This study evaluated the exposure of Finnish workers to airborne metals. It was conducted in 16 workplaces; 8 tool manufacturing companies (3 of which specialize in the maintenance of hard metal blades) and 8 blade repair shops in the mechanical wood-processing industry. The main emphasis of the study was on exposure in servicing (resharpening), especially involving wet-tip grinding processes. The results show that workers grinding hard metal blades may be exposed to high levels of airborne cobalt even when airborne total dust concentrations are low. The respirable proportion of the total dust was found to be high, and the total dust concentrations correlated well with the cobalt concentrations. Most of the airborne cobalt was water soluble (ionized), but there was also solid particles containing cobalt and other materials in the air of the workplaces. The mean concentration of cobalt in the grinding coolants was high, though it varied considerably. Concentrations of all the other metals measured in the air (tungsten, chromium, cadmium, silver, and nickel) and in the coolants (tungsten and chromium) were low. To reduce workers' exposure to cobalt, it is recommended that grinding machines should be enclosed and equipped with local exhausts. Use of coolants that dissolve less cobalt is also recommended, and the coolants should be changed more often. Brazing should be done in a well-ventilated place, and only cadmium-free materials should be used.