Nuclear medicine: workplace monitoring and internal occupational exposure during a ventilation/perfusion single-photon emission tomography.

The administration of 99mTc-HDP to diagnose pulmonary thromboembolisms leads to the presence of 99mTc in the environment of a nuclear medicine department, which could pose a potential risk of internal contamination to medical staff. Therefore, air samples from the administration room, gamma camera room and corridor of such a department were taken for the purpose of performing a workplace monitoring program of the medical centre under study, with maximum activity values of 640 ± 30 kBq/m3, 1.5 ± 0.1 kBq/m3 and 54 ± 3 kBq/m3, respectively, being obtained. These results correspond to committed effective doses received by exposed employees, via inhalation, when one ventilation/perfusion single-photon emission tomography study was performed, of 0.7 µSv, 0.004 µSv and 0.2 µSv, respectively. As inhalation is the employees' main exposure pathway to radio-aerosols, the internal dose of the nuclear medicine department's medical staff was also evaluated via urine bioassay measurements. Nuclear medicine nurses showed the highest 99mTc activity in 24-h urine samples (2100 ± 130 Bq/day), resulting in a committed effective dose of 21 µSv for each diagnostic study performed. Even so, the performance of ventilation/perfusion diagnostic studies did not constitute a substantial radiological risk since the annual dose limit for exposed employees was not exceeded.

Covalent organic frameworks as a novel fiber coating for solid-phase microextraction of volatile benzene homologues.

Covalent organic frameworks (COFs) have attracted great research interest due to their fascinating structures and potential applications in various fields. Here, the COF-SCU1 (SCU for Sichuan University) coated solid-phase microextraction (SPME) fibers were fabricated by coating it on prior functionalized stainless steel wires via a simple physical coating method, and applied to extract some volatile benzene homologues from indoor air samples. The main experimental parameters affecting the extraction efficiency were optimized, including extraction temperature, extraction time, and desorption time. The developed method, which combined the COF-SCU1 coated fiber-based SPME with gas chromatography-mass spectrometric detection, gave large enrichment factors (276-887), low limits of detection (0.03-0.15 ng L-1), and good linearity (0.10-20 ng L-1) for the determination of gaseous benzene homologues from three different indoor air samples. The precision (expressed as the relative standard deviations, RSDs) for six replicate determinations of the analytes at 10 ng L-1 each of the analytes using the same COF-SCU1 coated fiber ranged from 5.8 to 8.9%. The fiber-to-fiber reproducibility for three parallel COF-SCU1 coated fibers varied from 6.9 to 10.7%. The recoveries of the analytes for the method for the spiked indoor air samples with the benzene homologues at the two concentrations of 1 and 10 ng L-1 were in the range of 88.6-101.5% and 87.9-103.4% with the RSDs ranging from 3.9 to 10.3% and 3.4 to 8.5%, respectively. Graphical Abstract The covalent organic frameworks were applied as a novel fiber coating material for the solid-phase microextraction of volatile benzene homologues.

Feasibility and informative value of environmental sample collection in the National Children's Vanguard Study.

BACKGROUND: Birth cohort studies provide the opportunity to advance understanding of the impact of environmental factors on childhood health and development through prospective collection of environmental samples. METHODS: We evaluated the feasibility and informative value of the environmental sample collection methodology in the initial pilot phase of the National Children's Study, a planned U.S. environmental birth cohort study. Environmental samples were collected from January 2009-September 2010 at up to three home visits: pre-pregnancy (n=306), pregnancy (n=807), and 6-months postnatal (n=117). Collections included air for particulate matter ≤2.5 µm (PM2.5), nitrogen dioxide, ozone, volatile organic compounds (VOCs), and carbonyls; vacuum dust for allergens/endotoxin; water for VOCs, trihalomethanes (THMs), and haloacetic acids (HAAs); and wipe samples for pesticides, semi-volatile organics, and metals. We characterized feasibility using sample collection rates and times and informative value using analyte detection frequencies (DF). RESULTS: Among the 1230 home visits, environmental sample collection rates were high across all sample types (mean=89%); all samples except the air PM2.5 samples had collection times <30 min. Informative value was low for water VOCs (median DF=0%) and pesticide floor wipes (median DF=5%). Informative value was moderate for air samples (median DF=35%) and high for water THMs and HAAs (median DF=91% and 75%, respectively). CONCLUSIONS: Though collection of environmental samples was feasible, some samples (e.g., wipe pesticides and water VOCs) yielded limited information. These results can be used in conjunction with other study design considerations, such as target population size and hypotheses of interest, to inform the method selection of future environmental health birth cohort studies.

Environmental and occupational exposure to bisphenol compounds in Finland.

The aim of the study was to assess non-occupational and occupational exposure to bisphenol compounds in Finland. The participants were 151 non-occupationally exposed volunteers and 15 potentially exposed employees of a sewage-pipe relining company and a floor-coating company. The following chemicals were measured in the urine samples: bisphenol A (BPA), bisphenol F (BPF), bisphenol A diglycidyl ether (BADGE), bisphenol F diglycidyl ether (BFDGE), and the metabolites of the latter two [bisphenol A (2,3-dihydroxypropyl) glycidyl ether (BADGE·H2O), bisphenol A bis(2,3-dihydroxypropyl) ether (BADGE·2 H2O), bisphenol A (3-chloro-2-hydroxypropyl) (2,3-dihydroxypropyl) ether (BADGE·HCl·H2O), bisphenol A (3-chloro-2-hydroxypropyl) glycidyl ether (BADGE·HCl), and bisphenol A bis(3-chloro-2-hydroxypropyl) ether (BADGE·2HCl) and bisphenol F bis(2,3-dihydroxypropyl) ether (BFDGE·2 H2O), and bisphenol F bis(3-chloro-2-hydroxypropyl) ether (BFDGE·2HCl)]. BADGE and BFDGE were also measured in breathing zone air samples and hand-wipe samples of the sewage-pipe relining and floor-coating workers. Non-occupational exposure to BPA has decreased in Finland. The BPF level of the non-occupationally exposed was higher than the respective levels reported in the recent literature. BPA and BPF concentrations in the workers' urine samples were in the same range as those in the corresponding concentrations of the non-occupationally exposed population. Higher concentrations of BADGE and BFDGE metabolites were found in some of the workers' urine samples. Elevated urine concentrations were also observed in the samples collected the next morning. Some of the urinary BADGE and BFDGE metabolite results correlated with the hand-wipe results. The results show that occupational exposure to BADGE and BFDGE may occur in sewage-pipe relining and floor-coating work. They also indicate that dermal contamination plays a role in total exposure. Although the measured urinary levels indicate that the absorption of these bisphenol compounds are unlikely to pose a systemic health risk, the risk of dermal sensitization remains.

Mineralogical investigation of asbestos contamination of soil near old vermiculite processing plant in Honolulu, Hawai'i.

From 1954 to 1983, a vermiculite processing facility operated near the Honolulu airport and processed raw material from the Libby, Montana mine, which is now well known for the high asbestos content of its clay deposits. The factory was closed in 1983 due to health hazard concerns, and remediation was performed in 2001 as part of the Libby mine superfund project. However, because of close proximity of the closed-down facility to residential areas of metropolitan Honolulu, some concerns remain regarding the possible environmental persistence of the harmful contaminant. To assess the dispersion of asbestos-contaminated vermiculite and explore the impact of trade winds on its distribution, air samples, and soil samples were collected from multiple locations near the former vermiculite plant. Polarized light microscopy was employed to identify elongated minerals, including potential asbestos. Quantitative mineralogical analysis utilizing X-ray powder diffraction and Rietveld refinement revealed an average content of approximately 7% vermiculite and 4% tremolite at the site. The asbestiform nature of tremolite was confirmed through X-ray micro-diffraction. Detailed analysis of airborne samples using transmission electron microscopy revealed no detectable levels of asbestos fibers in the vicinity of the former processing facilities, but the possibility of asbestos fibers becoming airborne due to mechanical disturbance during dry weather cannot be ruled out.

Passive sampling of high production volume chemicals and polycyclic aromatic hydrocarbons in urban atmospheres near petrochemical sites: Uptake rate determination and application.

This study describes the use of passive sampling followed by pressurised liquid extraction and gas chromatography-mass spectrometry for monitoring high production volume chemicals (HPVCs), such as benzothiazoles, benzesulfonamides, phthalate esters (PAEs), organophosphate esters, ultraviolet stabilizers, and phenolic antioxidants and polycyclic aromatic hydrocarbons (PAHs) in urban atmospheres close to a petrochemical area. To obtain accurate results when applying passive sampling, the uptake rates of each target compound for the sampling time applied must be known. Firstly, passive sampling was calibrated for two months and uptake rates of HPVCs and PAHs in an urban atmosphere determined using active sampling as the reference method. The obtained results showed experimental diffusive uptake rates between 1.6 m3 day-1 and 27 m3 day-1 for 32 of the target compounds that will allow enable cost-effective long-term monitoring campaigns of HPVCs to be performed. Secondly, the experimentally obtained uptake rates were used to monitor the concentrations of HPVCs and PAHs at six urban sampling sites close to the two petrochemicals parks in Tarragona (Spain) during a period the two months. Regardless of the sampling campaign, PAEs and PAHs were the families of compounds found at the highest concentration levels, with a sum of their mean values of 23 ng m-3 and 20 ng m-3, respectively.

Shotgun metagenomic sequencing of swab samples from Japanese university campuses.

We obtained shotgun metagenome sequences from swab samples obtained through 3-minute swabbing of different surfaces and the air within buildings at three university campuses in part of the Greater Tokyo Area in Japan. These data aid in understanding built environment microbial communities and elucidate various microbial profiles across different locations.

A Novel Acremonium Species Isolated from Air Samples in Korea.

The aim of this study was to characterize a new fungal species, Acremonium conglutinatum, isolated from air samples collected in Wando, South Korea. Phylogenetic analysis based on the internal transcribed spacer and large subunit regions revealed its unique position within the genus Acremonium. The isolated strain displayed distinct morphological characteristics, including ellipsoid or bent-ellipsoid conidia formed in clusters on the phialides. These features differentiate the new species from closely related species within the genus. This study describes the morphological and molecular characteristics of A. conglutinatum and emphasizes its phylogenetic relationships with other Acremonium spp. The identification of this novel species contributes to our understanding of the diversity and ecological role of Acremonium.

Assessment of mold contamination in hurricane-damaged homes in Houston, Texas after sanitization by volunteers.

The purpose of this pilot study was to evaluate the effectiveness of mold sanitation in homes that suffered hurricane-related water damage. After a home is flooded, sanitation of the structure for mold is necessary before the interior of the home can be rebuilt. In this study, homes (n = 6) in Houston, Texas that had been flooded by Hurricane Harvey were sanitized by volunteers. At either 6, 8, 15, 25, 34, or 56 days after the sanitation was completed, a Button™ sampler was used to collect a 48-hour air sample, so that the mold cells in the air could be quantified. Each air sample was then analyzed by quantitative PCR (qPCR) assays for the 36 molds in the Environmental Relative Moldiness Index (ERMI) panel of indicator molds. Quantifying the 36-ERMI molds in air samples results in "ERMI-like" values. The ERMI-like values in the sanitized homes were inversely correlated (Pearson p - value 0.04) with the log of the number of days after the sanitation was completed, an indication that it takes time after sanitation for the mold levels to stabilize. This pilot study demonstrated that the ERMI-like metric was useful in assessing post-sanitation mold levels in previously flooded homes.

Evidence of Air and Surface Contamination with SARS-CoV-2 in a Major Hospital in Portugal.

As the third wave of the COVID-19 pandemic hit Portugal, it forced the country to reintroduce lockdown measures due to hospitals reaching their full capacities. Under these circumstances, environmental contamination by SARS-CoV-2 in different areas of one of Portugal's major Hospitals was assessed between 21 January and 11 February 2021. Air samples (n = 44) were collected from eleven different areas of the Hospital (four COVID-19 and seven non-COVID-19 areas) using Coriolis® µ and Coriolis® Compact cyclone air sampling devices. Surface sampling was also performed (n = 17) on four areas (one COVID-19 and three non-COVID-19 areas). RNA extraction followed by a one-step RT-qPCR adapted for quantitative purposes were performed. Of the 44 air samples, two were positive for SARS-CoV-2 RNA (6575 copies/m3 and 6662.5 copies/m3, respectively). Of the 17 surface samples, three were positive for SARS-CoV-2 RNA (200.6 copies/cm2, 179.2 copies/cm2, and 201.7 copies/cm2, respectively). SARS-CoV-2 environmental contamination was found both in air and on surfaces in both COVID-19 and non-COVID-19 areas. Moreover, our results suggest that longer collection sessions are needed to detect point contaminations. This reinforces the need to remain cautious at all times, not only when in close contact with infected individuals. Hand hygiene and other standard transmission-prevention guidelines should be continuously followed to avoid nosocomial COVID-19.

Revisiting SARS-CoV-2 environmental contamination by patients with COVID-19: The Omicron variant does not differ from previous strains.

SARS-CoV-2 Omicron strain emergence raised concerns that its enhanced infectivity is partly due to altered spread/contamination modalities. We therefore sampled high-contact surfaces and air in close proximity to patients who were verified as infected with the Omicron strain, using identical protocols applied to sample patients positive to the original or Alpha strains. Cumulatively, for all 3 strains, viral RNA was detected in 90 of 168 surfaces and 6 of 49 air samples (mean cycle threshold [Ct]=35.2±2.5). No infective virus was identified. No significant differences in prevalence were found between strains.

Cough associated with the detection of Mycoplasma hyopneumoniae DNA in clinical and environmental specimens under controlled conditions.

BACKGROUND: The association of cough with Mycoplasma hyopneumoniae (MHP) DNA detection in specimens was evaluated under conditions in which the MHP status of inoculated and contact-infected pen mates was closely monitored for 59 days post-inoculation (DPI). METHODS: Seven-week-old pigs (n = 39) were allocated to five rooms (with one pen). Rooms contained 9 pigs each, with 1, 3, 6, or 9 MHP-inoculated pigs, respectively, except Room 5 (three sham-inoculated pigs). Cough data (2 × week) and specimens, tracheal swabs (2 × week), oral fluids (daily), drinker wipes (~ 1 × week), and air samples (3 × week) were collected. At 59 DPI, pigs were euthanized, and lung and trachea were evaluated for gross and microscopic lesions. Predictive cough value to MHP DNA detection in drinker and oral fluid samples were estimated using mixed logistic regression. RESULTS: Following inoculation, MHP DNA was first detected in tracheal swabs from inoculated pigs (DPI 3), then oral fluids (DPI 8), air samples (DPI 10), and drinker wipes (21 DPI). MHP DNA was detected in oral fluids in 17 of 59 (Room 1) to 43 of 59 (Room 3) samples, drinker wipes in 4 of 8 (Rooms 2 and 3) to 5 of 8 (Rooms 1 and 4) samples, and air samples in 5 of 26 (Room 2) or 3 of 26 (Room 4) samples. Logistic regression showed that the frequency of coughing pigs in a pen was associated with the probability of MHP DNA detection in oral fluids (P < 0.01) and nearly associated with drinker wipes (P = 0.08). Pathology data revealed an association between the period when infection was first detected and the severity of gross lung lesions. CONCLUSIONS: Dry, non-productive coughs suggest the presence of MHP, but laboratory testing and MHP DNA detection is required for confirmation. Based on the data from this study, oral fluids and drinker wipes may provide a convenient alternative for MHP DNA detection at the pen level when cough is present. This information may help practitioners in specimen selection for MHP surveillance.

Comparison of multiple calibration approaches for the determination of volatile organic compounds in air samples by solid phase microextraction Arrow and in-tube extraction.

Several calibration approaches were evaluated for the quantitation of volatile organic compounds in air using miniaturized exhaustive and non-exhaustive sampling techniques, such as in-tube extraction (ITEX) and solid phase microextraction (SPME) Arrow. Eleven compounds, 2-ethyl-hexanol, hexanal, nonanal, toluene, ethyl-benzene, methyl isobutyl ketone, acetophenone, p-cymene, α-pinene, trimethylamine and triethylamine, all them found in the natural air samples, were selected as model analytes. Liquid injection, liquid standard addition to the sorbent bed and gas phase standards provided by an automatic permeation system, were evaluated in the case of ITEX packed with laboratory-made 10% polyacrylonitrile (PAN) material. Two different approaches, based on sampling of gas phase compounds from the permeation system and from sample vial containing gas phase standards, were evaluated for SPME Arrow with two different coatings, commercial divinylbenzene-poly(dimethylsiloxane) (DVB-PDMS) and laboratory-made mesoporous Mobil Composition of Matter No. 41 (MCM-41). In addition, interface model approach was used for the calculation of the real concentration of the target analytes in the sample from the total amount of analytes injected into the GC-MS in the case of SPME Arrow. Similar results were obtained with the different approaches used for the quantitation by ITEX and SPME Arrow. However, the use of gas phase standards with sample matrix similar to the natural samples, allowed the permeation system to provide the most reliable results for the quantitation of the target analytes. For this approach, linearity (expressed as r2 values) ranged between 0.991 and 0.999. The limit of detection ranged from 0.5 µg/m3 (trimethylamine, MCM-41) to 2.2 × 10-4 µg/m3 (methyl isobutyl ketone, MCM-41). In addition, the use of the fully automated permeation system provided good reproducibility values that were between 1.4% (acetophenone, MCM-41) and 7.8% (methyl isobutyl ketone, 10% PAN). The linear ranges were at least 3 order of magnitude for all the studied analytes with the exception of the calibration curve developed for trimethylamine with SPME Arrow (linear ranges between LOQ and 4.9 µg/m3 (DVB-PDMS) and LOQ and 9.8 µg/m3 (MCM-41)).

Levels of Airborne Soybean Allergen (Gly m 1) in a Brazilian Soybean Production City: A Pilot Study.

Asthma epidemics have been shown to be related to where soybeans are loaded and handled, but data are scarce in the literature. This pilot study evaluated the levels of Gly m 1 in dust samples collected in Maringá, Brazil, a city with high soy production and processing. A dust impactor was used to collect seven isolated samples during 2015 and 2016. Samples were analyzed by an ELISA (enzyme-linked immunosorbent assay) detection method. Gly m 1 was found in all samples, ranging from 0.82-24.38 ng/m3 (median 2.41), regardless of the month or year evaluated. The levels of Gly m 1 were considered low, but the concentrations required to cause sensitization and symptoms are uncertain.

Occupational Exposure of Plastics Workers to Diisononyl Phthalate (DiNP) and Di(2-propylheptyl) Phthalate (DPHP) in Finland.

The aim of this study was to assess occupational exposure to diisononyl phthalate (DiNP) and di(2-propylheptyl) phthalate (DPHP] in Finland. Four companies took part in the research project: A cable factory, a plastic producing company, a producer of coated textiles, and a tarpaulin producer. The cable factory used DPHP (and occasionally also diisodecyl phthalate, DiDP), the plastic producing company used both DPHP and DiNP, and the latter two companies used DiNP in their production. Exposure was assessed by measuring phthalate metabolites in urine samples (biomonitoring) and by performing air measurements. Low-level occupational exposure to DiNP was observed in the company that produced coated textiles-out of eight workers, one extruder operator was exposed to DiNP at levels exceeding the non-occupationally exposed population background levels. Some workers in the cable factory and the plastics producing company were occupationally exposed to DPHP. Air levels of phthalates were generally low, mostly below the limit of quantification. All phthalate metabolite concentrations were, however, well below the calculated biomonitoring equivalents, which suggests that the health risks related to the exposure are low.

Sensors' array of aspiration ion mobility spectrometer as a tool for bacteria discrimination.

The possibility of achieving bacterial discrimination using a miniaturized aspiration ion mobility spectrometer model ChemPro-100i (Environics Oy) has been tested by interrogating the headspace air samples above in vitro bacterial cultures of three species - Escherichia coli, Bacillus subtilis and Staphylococcus aureus, respectively. The ChemPro-100i highly integrated seven sensor array, composed of one a-IMS cell, three MOS (metal oxide sensors), one FET (field effect transistor) sensor and two SC (semiconductor) sensors, provided enough analytical information to discriminate between the three bacterial species. Statistical data processing using either principal component analysis (PCA) or partial least squares discriminant analysis (PLS-DA) was accomplished. We concluded that although the data from the aspiration-type ion mobility sensor, with its 16 ion detectors, is absolutely sufficient to discriminate between various bacteria using their volatile compounds' chemical profile, the other six sensors deliver additional, valuable information.

Airborne Pheromone Quantification in Treated Vineyards with Different Mating Disruption Dispensers against Lobesia botrana.

Mating disruption (MD) is widely used against the European grapevine moth (EGVM), Lobesia botrana (Denis and Schiffermüller; Lepidoptera: Tortricidae), by installing passive dispensers or aerosol devices. The present work reports a new sampling and quantification methodology to obtain absolute data about field airborne pheromone concentration based on air samplings and sensitive chromatographic-spectroscopic methods. Samplings were performed in fields treated with passive dispensers or aerosol devices at different moments throughout the crop cycle to study how they act and how the disruption is triggered. Moreover, pheromone adsorption and releasing capacity of vine leaves were studied to elucidate their role in the disruption. Although both types of dispensers were effective in limiting the damage inflicted by EGVM, they performed differently and provided different airborne pheromone concentration profiles. Results also proved that leaves were able to adsorb and release part of the airborne pheromone acting as subsequent and additional pheromone sources. This fact could explain the different concentration profiles. Moreover, our results suggest that lower pheromone emission than that of the current passive dispensers still could provide an adequate performance in the field. Competitive mechanisms involved in MD using both dispensers, the dynamics of the airborne pheromone throughout the time and the importance of the canopy are discussed.

Characteristics of atmospheric fungi in particle growth events along with new particle formation in the central North China Plain.

The importance of fungi as cloud condensation nuclei (CCN) and ice-forming nuclei (IN) has been recognized for some researches. Particle growth along with new particle formation (NPF) play a joint role in modulating the CCN number concentration. Although fungi can accelerate the coalescence by large particles, the specific contribution and characteristics of atmospheric fungi for particle growth, especially during NPF events, is poorly understood. In this study, aerosol size distribution data and air samples were collected at Xingtai, a suburban site in the central North China Plain, from 1 May to 1 June 2016. Using DNA sequence-based methods, atmospheric fungal communities were identified and quantified. Significant differences in fungal communities between particle growth events along with new particle formation (PGE-NPF) and non-PGE-NPF events are found, especially for the Ascomycota and Basidiomycota phyla, and the Dothideomycetes, Saccharomycetes, and Tremellomycetes classes. At the genus level, five fungal communities were significantly different under PGE-NPF and non-PGE-NPF conditions, i.e., the Cladosporium, Capnodiales, Mrakia, Saccharomycetales and Trichocomaceae genera. The air mass source not only had an impact on NPF and the particle growth process, but also on the characteristics of the fungal communities. The fungal genus communities of Cladosporium, Capnodiales, Trichocomaceae, Mrakia, and Saccharomycetales may contribute to NPF and the particle growth process.

Evaluation of sampling adsorbents and validation of a LC-HRMS method for determination of 28 airborne pesticides.

A new strategy for sampling, using a low-volume sampler, and determination of airborne pesticides by liquid chromatography coupled to high-resolution mass spectrometry (UHPLC-HRMS) has been developed. The trapping efficiency of three adsorbents (sandwich PUF-XAD2-PUF; XAD-2 and XAD-4) was tested for 33 currently used pesticides and the first adsorbent (PUF-XAD2-PUF) was selected because it presented the highest retention capacity without breakthrough. Selected PUF-XAD2-PUF had the following design: 5 g of Amberlite XAD-2 sandwiched between two cylinders of PUF (6.87 cm3, height: 1.4 cm, diameter: 2.5 cm). A validation of the analytical methodology that includes microwave extraction with ethyl acetate, and determination by UHPLC-HRMS was employed. The method showed recoveries ranging from 75% to 120% with quantification limits in the range of 32.2-129.0 pg m-3 when 155 m3 were sampled. This analytical strategy was applied to 15 air samples collected in a rural area of Valencia Region (Spain). Ten polar pesticides, namely acetamiprid, carbendazim, carbofuran, imidacloprid, iprovalicarb, metalaxyl, myclobutanil, pirimicarb, pyrimethanil and terbuthylazine were detected in air samples with concentrations ranging from 411.16 pg m-3 (imidacloprid) to 11011.45 pg m-3 (pyrimethanil).

Environmental and occupational exposure to resorcinol in Finland.

Resorcinol is a suspected endocrine disruptor that affects thyroid function by inhibiting thyroxin peroxidase. It may also have an impact on iodine uptake. Resorcinol has various uses; for example in the manufacture of rubber products and in wood adhesives, flame retardants, UV stabilizers, and dyes. It is also used in personal care products such as hair colorants, anti-acne preparations, and peels. The aim of this study was to assess both environmental background exposure and occupational exposure to resorcinol in Finland. We investigated occupational exposure in hairdresser work and in the manufacture of tyres, adhesive resins and glue-laminated timber by biomonitoring total resorcinol concentration in urine samples. The biomonitoring results were compared to the urinary levels of occupationally non-exposed volunteers, and to the biomonitoring equivalent (BE), which we estimated on the basis of the EFSA's acceptable daily intake (ADI) value for resorcinol. Almost all the urine samples (99%) of the non-occupationally exposed volunteers contained measurable amounts of resorcinol. The urinary resorcinol data were rather scattered, and the resorcinol concentrations among women (GM 84 µg/l, 95th percentile 2072 µg/l) were clearly higher than the respective concentrations among men (GM 35 µg/l, 95th percentile 587 µg/l). The reason for this difference remains unclear. Although the two highest results exceeded the BE of 4 mg/l calculated on the basis of the EFSA's ADI, the 95th percentile of the occupationally non-exposed volunteers' results remained well below the BE among both males and females. According to the results, hairdressers' exposure to resorcinol was at the same level as that of the reference population of occupationally non-exposed volunteers. All hairdresser's values remained below the BE for resorcinol. The urinary resorcinol levels of the industrial workers were also at the same level as those of the reference population. We observed slight increases in the post-shift and evening samples of those working in the manufacture of tyres and adhesive resins. The results of some workers in the tyre manufacturing company exceeded the 95th percentile of non-occupationally exposed males, which was used as a biological guidance value for occupational exposure. Moreover, in this case exposure was below the health-based biomonitoring equivalents. All the air samples collected in the companies contained very low resorcinol concentrations. It should be noted that the sample sizes for the male controls and industrial groups were small.