Cancer incidence in a cohort of Danish firefighters: An extended long-term follow-up 1968-2021.

OBJECTIVES: To update and extend the examination of cancer incidence in a cohort of Danish firefighters, now adding 7 years of follow-up and 2766 additional firefighters. The primary focus was directed toward cancer sites that recently contributed to the hazard evaluation conducted by the International Agency for Research on Cancer (IARC). METHODS: The updated cohort consisted of 11,827 male Danish firefighters who were followed up for cancer from 1968 to 2021. Cohort cancer morbidity was compared with a working population reference group, and standardized incidence ratios (SIR) were used for estimation of relative risks, along with 95% confidence intervals (95% CI). RESULTS: Among full-time firefighters, SIR of skin melanoma was 1.30 (95% CI: 1.02-1.66), and SIR = 1.37 (95% CI: 1.02-1.85) for over 5 years of employment. Slightly positive associations were also observed for cancer of the urinary bladder (SIR = 1.16; 95% CI: 0.93-1.45), prostate (SIR = 1.11; 95% CI: 0.97-1.28), and testis (SIR = 1.11; 95% CI: 0.75-1.63). CONCLUSIONS: This updated study provides evidence indicating an elevated risk of skin melanoma in firefighters. Consistent with IARC's evaluation, we also identified positive associations for urinary bladder, prostate, and testis cancer. In contrast, our findings did not suggest an increased risk of colon cancer, non-Hodgkin lymphoma, and mesothelioma. The latter may be due to small numbers in our still relatively young cohort. Continuous follow-up for cancer in firefighters is warranted, including assessment of influence from surveillance bias.

Hand eczema and temporal variation of Staphylococcus aureus clonal complexes: A prospective observational study.

BACKGROUND: Hand eczema (HE) is frequently associated with Staphylococcus aureus; however, its role in the pathogenesis of HE is poorly understood. OBJECTIVE: To investigate the temporal variation in S aureus subtypes, ie, clonal complex (CC) types, on the hands and relate it to S aureus colonization in the nose and severity in a cohort of HE patients. METHODS: S aureus from the hands and nose of 50 adult HE patients and 50 controls was prospectively identified at 5 visits over 3 weeks. RESULTS: S aureus was identified on the hands of 23 (46%) patients at 2 or more visits and on the hands of 1 control once. Of the HE patients with S aureus colonization, 78% had the same S aureus CC type over time. Twenty-one patients had the same S aureus CC type on the hands and in the nose. Persistent colonization was strongly related to an increased disease severity. LIMITATIONS: A relatively small S aureus culture-positive population. CONCLUSION: The temporal stability of S aureus CC type and high occurrence of the identical subtypes on the hands and in the nose imply that S aureus colonization in patients with HE is of a more permanent nature. Taken together with the finding that persistent colonization and HE severity are clearly related, our results indicate that S aureus may contribute to the perpetuating course of HE.

An update on the prevalence and risk exposures associated with hand eczema in Danish hospital employees: A cross-sectional questionnaire-based study.

BACKGROUND: Hand eczema (HE) is common in health care workers (HCWs). During the last decade, new recommendations have supported increased use of alcohol-based hand rub (ABHR) to partially replace hand washings to lower the prevalence of HE. However, newer data on this recommendation is lacking. OBJECTIVES: To assess current 1-year prevalence of HE in HCWs, to investigate exposure, and the extent of subjective discomfort to hand washings and ABHR. METHODS: A digital questionnaire was sent to 4876 HCWs from April to May 2020. RESULTS: Of 2125 respondents (1779 women, 346 men), 14.7% reported HE within the last year. In total, 9.1% reported >20 hand washings per shift and 76.0% reported ABHR use >20 times per shift. HE was significantly associated with hand washings (adjusted odds ratio [OR] 1.73 [95% confidence interval [CI] 1.26-2.36]) and glove use on wet skin (adjusted OR 1.99 [95% CI 1.27-3.12]). Subjective discomfort to ABHR was reported significantly more often than to hand washings (P < .001) and significantly more often in HCWs with HE than in those without HE (P < .001). CONCLUSIONS: The current 1-year HE prevalence in HCWs of 14.7% was lower than in previously reported Scandinavian data. HE was related to frequent hand washings, as previously reported, and to glove use on wet skin, which is a possible risk factor for HE that should be further explored.

Systemic therapy and the use of complementary and alternative medicine in patients with recognized occupational hand eczema in Denmark: A cross-sectional questionnaire-based study.

BACKGROUND: Concerns have been raised that a chronic course of hand eczema (HE) could be fostered by a lack of efficient treatment at an early stage. OBJECTIVES: First, to assess the prevalence of systemic treatment in patients with chronic occupational HE (OHE) and relate this to demographic data, HE severity, and atopic dermatitis (AD). Second, to explore the use of complementary and alternative medicine (CAM) in the same population. METHODS: Baseline data were obtained from a registry-based study including patients with recognized OHE in a 2-year period in Denmark, comprising a total of 2703 workers. A follow-up questionnaire after 4 to 5 years included questions on disease severity and treatments. RESULTS: A total of 1565 participants responded to the questionnaire, and of these 1203 had ongoing HE at follow-up and were included in the study. In total, 10.0% had received systemic therapy, whereas this share was 13.3% in those with self-reported moderate-to-severe HE. Age >35 years, previous or current AD, and severe eczema were factors related to use of systemic treatment. Use of CAM was reported by 6.2% of the study population. CONCLUSIONS: We suggest that chronicity of HE may be perpetuated by the lack of efficient treatment.

Colonization with Staphylococcus aureus in patients with hand eczema: Prevalence and association with severity, atopic dermatitis, subtype and nasal colonization.

BACKGROUND: While Staphylococcus aureus (S. aureus) colonization has been thoroughly studied in atopic dermatitis (AD), where S. aureus is related to flares and considered a trigger factor, S. aureus colonization in hand eczema (HE) has only been sparsely studied. OBJECTIVES: To examine the 1-week prevalence of S. aureus colonization in HE patients, and its association with severity, HE subtype, AD, and nasal S. aureus colonization compared with healthy controls. METHODS: In a case-control study of 50 adult HE patients and 50 healthy controls, bacterial swabs from lesional skin (patients only), non-lesional skin (dorsal hand), and the nasal cavity were sampled for culturing of S. aureus on days 1, 3, 5 and 8. Participants were characterized by demographics, AD, HE subtype, filaggrin gene mutation status, and HE severity. RESULTS: Twenty-seven HE patients (54%) were colonized with S. aureus on the hand compared to one control (2%) (P < .01). Nasal S. aureus colonization was found in 72% of patients and 22% of controls (P < .01). For patients, S. aureus colonization on the hands was associated with an atopic HE subtype and HE severity (P = .01 and P < .01, respectively). CONCLUSIONS: Both hand and nasal S. aureus colonization were highly prevalent among HE-patients and may have an impact on the persistence of HE.

Hand eczema patients' knowledge of skin protection following a guided talk-A retrospective study with a follow-up questionnaire.

BACKGROUND: Several studies have assessed the effect of patient education regarding hand eczema (HE) severity and quality of life. Few studies, however, have evaluated patients' knowledge. OBJECTIVES: To examine knowledge of skin protection in HE patients following a guided talk, and to identify variables associated with knowledge. METHODS: HE patients referred to the outpatient dermatological clinic, Bispebjerg Hospital, between January 2013 and July 2014 were offered a guided talk on HE prevention. HE severity and the Dermatology Life Quality Index (DLQI) score were assessed. A questionnaire comprising 10 questions about skin protection was sent 1 to 2.5 years later. RESULTS: One hundred and twenty patients responded to the questionnaire (response 53.5%). The mean percentage of correct answers was 74.7%. Sixty per cent responded correctly to at least eight questions. Male sex, older age and education for >5 years were associated with a low level of knowledge. Education for 3 to 4 years (P = 0.045) was associated with a higher level of knowledge. No significant impact of previous/current atopic dermatitis, HE severity or previous information on skin protection was found with respect to level of knowledge. CONCLUSIONS: Females and patients with education for 3 to 4 years showed the highest level of knowledge, whereas males, older patients and patients with education for >5 years should be brought more into focus in skin protection programmes.

Occupational hand eczema and/or contact urticaria: factors associated with change of profession or not remaining in the workforce.

BACKGROUND: Occupational hand eczema and/or contact urticaria may have social consequences such as change of profession or not remaining in the workforce. OBJECTIVES: To identify factors associated with job change in a cohort of participants with recognised occupational hand eczema/contact urticaria METHODS: A registry-based study including 2703 employees with recognised occupational hand eczema/contact urticaria in Denmark in 2010/2011. Four to five years later the participants received a follow-up questionnaire, comprising questions on current job situation (response rate 58.0%). RESULTS: At follow-up, 51.3% of the participants were no longer in the same profession. 32.5% had changed profession and 18.8% were no longer in employment. Change of profession was associated with young age, positive patch test, low educational level and severity of hand eczema/contact urticaria. With regard to specific professions, cleaning personnel changed profession significantly more often than other workers [71.4% (OR = 2.26)], health care workers significantly less often than other workers [34.0% (OR = 0.36)]. CONCLUSION: Job change occurs frequently during the first years after recognition of occupational hand eczema/contact urticaria and more often among patients with positive patch test reactions, with severe hand eczema/contact urticaria. Whether job changes improve the prognosis of occupational hand eczema/contact urticaria remains to be established.

Impact of hand eczema on quality of life: metropolitan versus non-metropolitan areas.

BACKGROUND: An inverse relationship between disease severity and health-related quality of life (HR-QoL) in patients with hand eczema is well established, but modifying effects of demographic variables have been less well studied. OBJECTIVE: To identify the influence of metropolitan versus non-metropolitan residence on the relationship between disease severity and HR-QoL in patients with occupational hand eczema. METHODS: The city of Copenhagen and the rest of Zealand were defined as metropolitan and non-metropolitan areas, respectively. Participants were 773 persons with occupational hand eczema. A questionnaire on the severity of hand eczema and HR-QoL was sent to all participants. RESULTS: The odds for reporting moderate to high severity of occupational hand eczema were significantly lower in the metropolitan population than in the non-metropolitan population [odds ratio (OR): 0.42; 95%CI: 0.23-0.75], whereas low dermatology-related quality of life was more prevalent in metropolitan than in non-metropolitan patients (OR: 1.31; 95%CI: 0.83-2.05), indicating that hand eczema had a more pronounced negative effect in metropolitan patients, in spite of less severe eczema. CONCLUSION: Our data indicate that area of residence has a modifying effect on the relationship between disease severity and HR-QoL, with a more negative impact on HR-QoL in metropolitan than in non-metropolitan areas. This information is important with respect to fully appreciating the burden of occupational hand eczema.

Hand eczema and wet work: dose-response relationship and effect of leaving the profession.

BACKGROUND: Wet work is an important risk factor for occupational hand eczema. OBJECTIVES: To examine the effect of job change in workers with occupational hand eczema caused by wet work, and to evaluate the dose-response relationship between intensity of wet work and eczema. METHOD: The study is based on a subgroup (n = 954) from a descriptive, registry-based study including all participants with occupational hand eczema caused by wet work recognized by the Danish Labour Market Insurance Authority in 2010 and 2011. A follow-up questionnaire was sent out 4-5 years later (response 58%). RESULTS: Change of profession and being outside the labour market had a positive effect on healing and improvement of hand eczema. Inverse dose-response relationships were found between the amount of time spent with wet hands at work and healing (p = 0.001) and improvement (p < 0.001), and between the frequency of hand washing at work and healing (p = 0.013) and improvement (p < 0.001). CONCLUSIONS: Leaving the profession has a positive effect on eczema; however, even minor changes in exposure to wet work were associated with healing and improvement. This information has implications with respect to advice given to patients with occupational hand eczema caused by wet work.

Simple, low-cost group-counselling programme vs treatment as usual for patients with newly notified occupational hand eczema-Exploratory analyses of effects on knowledge, behaviour and personal resources of the randomized PREVEX clinical trial.

BACKGROUND: Sickness absence in hand eczema patients has been associated with stress rather than disease severity, indicating that personal aspects regarding hand eczema should be investigated further. OBJECTIVES: To examine whether patient education vs treatment as usual can influence behaviour and knowledge regarding skin protection and care, as well as personal resources, in patients with occupational hand eczema. METHODS: PREVEX is an individually randomized clinical trial investigating the 1-year effects of a simple, low-cost group-counselling programme vs treatment as usual for patients with notified occupational hand eczema. Exploratory outcomes were behaviour, knowledge, self-efficacy, and self-evaluated skin care ability. RESULTS: In total, 1668 patients with notified occupational skin disease were invited to participate, of whom 769 were randomized and 756 were analysed: intervention group (n = 376) vs control group (n = 380). Behaviour was improved and the knowledge score increased in the intervention group as compared with the control group (respectively: estimate 0.08; 95%CI: 0.02-0.19; P = .01; and estimate 0.49; 95%CI: 0.28-0.70; P < .001). Self-efficacy was lower in the intervention group as compared with the control group (estimate -0.78; 95%CI: -1.25 to -0.30; P = .001). No difference was found regarding skin care abilities. CONCLUSIONS: The intervention had a positive influence on 1-year behaviour and knowledge, but was insufficient to result in long-term positive changes in personal resources regarding dealing with hand eczema.

Occupational dermatitis in hairdressers - influence of individual and environmental factors.

BACKGROUND: Hairdressers are at risk of developing occupational contact dermatitis because of their intense contact with wet work in combination with chemicals. OBJECTIVES: To perform an analysis of a cohort study of hairdressers with occupational contact dermatitis recognized in the period 2006-2011, focusing on individual and environmental factors associated with the disease. METHODS: The study was a descriptive, register-based survey including all hairdressers with recognized occupational contact dermatitis in Denmark in the period January 2006 to September 2011. Data were obtained from the Danish National Board of Industrial Injuries. RESULTS: The study comprised 381 patients (373 women and 8 men). The median age was 25 years, 64.8% were apprentices, and 35.2% were fully trained hairdressers. The prevalence of atopic dermatitis was 36.0%, and was significantly higher among apprentices than among fully trained hairdressers (44.9% and 19.4%, respectively) (p < 0.001). Of the patients, 48.3% had their dermatitis recognized as occupational irritant contact dermatitis, 46.7% had their dermatitis recognized as as occupational allergic contact dermatitis or combined allergic and irritant contact dermatitis, and 5.0% were recognized as having occupational contact urticaria. CONCLUSION: The low median age, the high percentages of atopic dermatitis in apprentices and the fact that more apprentices than fully trained hairdressers had recognized occupational contact dermatitis underlines the importance of early prevention.

Associations between lifestyle factors and hand eczema severity: are tobacco smoking, obesity and stress significantly linked to eczema severity?

BACKGROUND: It has been suggested that lifestyle factors such as smoking, overweight and stress may influence the prevalence and severity of hand eczema. OBJECTIVES: To investigate the association between lifestyle factors and hand eczema severity in a cohort of patients with work-related hand eczema. METHODS: Individuals with work-related hand eczema notified in the period between June 2012 and November 2013 were included in this questionnaire-based cross-sectional study. Participants responded to a questionnaire including questions on lifestyle factors, as well as a photographic guide for assessment of severity of hand eczema and questions on quality of life. RESULTS: A total of 773 individuals (546 women and 227 men) responded to the questionnaire and were included in the study. A strong association was found between tobacco smoking and hand eczema severity (p = 0.003), whereas no significant association was found for body weight and stress. Other factors linked to severe eczema were male sex and older age (p = 0.04 and p = 0.01, respectively), and wet work (p = 0.08). CONCLUSION: The data from the present study strongly support an association between smoking and hand eczema severity. However, owing to the cross-sectional design of the study, no conclusion on causation can be drawn.

Occupational allergic contact dermatitis in a 2-year follow-up study: how well does the patient remember the result of patch testing?

BACKGROUND: Patch testing is mandatory for diagnosing contact dermatitis. It is, however, crucial that patients understand and remember the result of the test. OBJECTIVES: The aim of our study was to evaluate the impact of patch testing with respect to patients' ability to remember patch test results and the results of natural rubber latex protein allergy after 2 years. METHODS: One hundred and ninety-nine patients diagnosed with relevant occupational epoxy or rubber chemical contact allergy, or allergy to natural rubber latex protein, were invited to participate in a questionnaire study about their knowledge of contact allergies after 2 years. RESULTS: The response rate was 75%. Of the respondents, 13% did not remember their occupational contact allergy to rubber chemicals or epoxy. Ability to remember was not significantly influenced by sex or Dermatology Life Quality Index, but was decreased by age >60 years (p < 0.01). Of patients with an additional contact allergy, <36% remembered this correctly. Of patients allergic to natural rubber latex proteins, 50% remembered this correctly. CONCLUSIONS: The impact of patch testing depends on the patients' ability to understand and remember the results of the test. Attention should be drawn to the importance of this, and patients with increased need for information should be identified.

Evidence-based training as primary prevention of hand eczema in a population of hospital cleaning workers.

BACKGROUND: Skin disorders accounted for one third of all recognised occupational diseases in Denmark in 2010. Wet work is a risk factor for the development of occupational hand eczema. The consequences of occupational hand eczema include sick leave, loss of job and impaired quality of life. OBJECTIVES: The aim of the present study was to investigate exposures related to cleaning and the effect of an evidence-based educational intervention on the prevention of hand eczema among hospital cleaners. PATIENTS/MATERIALS/METHODS: The intervention consisted of a 1 hr course in hand protective behaviour. All full-time cleaners working at Bispebjerg Hospital in January 2013 were invited to participate. The outcome measures were self-reported skin behaviour, exposures, knowledge of skin protection and hand eczema severity index (HECSI). RESULTS: One hundred and five cleaners were invited to participate, of these 86 (82%) were included. At follow-up after 3 months there was a shift towards fewer daily hand washings and hand disinfections (p < 0.001 and p = 0.001 respectively). The number of correct answers to the knowledge questions rose from 6.3 to 7.3 (p = 0.006). The mean HECSI score decreased from 2.8 to 1.8 at follow-up (p = 0.002). CONCLUSIONS: Data indicates a positive effect of a low-cost on-site educational intervention for hospital cleaners.

The Underlying Mechanism of Poisoning after the Accidental Inhalation of Aerosolised Waterproofing Spray.

Waterproofing sprays can cause acute respiratory symptoms after inhalation, including coughing and dyspnoea shortly after use. Here, we describe two cases where persons used the same brand of waterproofing spray product. In both cases the persons followed the instructions on the product and maximized the ventilation by opening windows and doors; however, they still became affected during the application of the product. Products with the same batch number as that used in one case were tested for their effect on respiration patterns of mice in whole-body plethysmographs and lung surfactant function inhibition in vitro. The product was used in spraying experiments to determine the particle size distribution of the aerosol, both using a can from one case and a can with an identical batch number. In addition, the aerosols in the mouse exposure chamber were measured. Aerosol data from a small-scale exposure chamber and data on the physical and temporal dimensions of the spraying during one case were used to estimate the deposited dose during the spraying events. All collected data point to the spraying of the waterproofing product being the reason that two people became ill, and that the inhibition of lung surfactant function was a key component of this illness.

Protocol for a randomised trial on the effect of group education on skin-protective behaviour versus treatment as usual among individuals with newly notified occupational hand eczema - the Prevention of Hand Eczema (PREVEX) Trial.

BACKGROUND: The incidence of occupational hand eczema is approximately 0.32 per 1,000 person years. The burden of the disease is high, as almost 60% has eczema-related sick leave during the first year after notification, and 15% are excluded from the workforce 12 years after disease onset. New treatments and prevention strategies are needed. TRIAL DESIGN: The PREVEX trial is a randomised, parallel-group, superiority trial. PARTICIPANTS: All individuals from the Capital Region of Denmark and Region Zealand with a suspected occupational skin disorder notified to the National Board of Industrial Injuries between June 2012 and December 2013 are invited to participate in the trial. Inclusion criteria are: self-reported hand eczema and informed consent. Exclusion criteria are: age <18 years or >65 years; permanent exclusion from the workforce; inability to understand the Danish language; any serious medical condition; and lack of written informed consent. We plan to randomise 742 participants. INTERVENTIONS: The experimental intervention is an educational course in skin-protective behaviour and written information about skin care related to the participants' specific occupation. Also, a telephone hotline is available and a subgroup will be offered a work-place visit. The experimental and the control group have access to usual care and treatment. All participants are contacted every eighth week with questions regarding number of days with sick leave or other absence from work. 12 months after randomisation follow-up is completed. OBJECTIVE: To assesses the effect of an educational course versus treatment as usual in participants with newly notified occupational hand eczema. Randomisation: PARTICIPANTS are centrally randomised according to a computer-generated allocation sequence with a varying block size concealed to investigators. Blinding: It is not possible to blind the participants and investigators, however, data obtained from registers, data entry, statistical analyses, and drawing of conclusions will be blinded. OUTCOMES: The three co-primary outcomes, assessed at 12 months, are: total number of self-reported days with sick leave; health-related quality of life; and subjective assessment of hand eczema severity. Explorative outcomes are: self-reported eczema-related sick leave, absence from work registered by the DREAM-register and by self-report, risk behaviour, knowledge of skin protection and performance management (self-efficacy; and self-evaluated ability to self-care). DISCUSSION: The PREVEX trial will be the first individually randomised trial to investigate the benefits and harms of group-based education in patients with newly notified occupational hand eczema. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT01899287.

What do patients with occupational hand eczema know about skin care?

BACKGROUND: The aim of the present study was to examine the knowledge of skin care and treatment of hand eczema (HE) in a sample of patients with newly reported occupational HE. MATERIALS AND METHODS: A questionnaire consisting of 13 questions about knowledge of skin care and treatment of HE was sent to all patients with occupational HE reported to the National Board of Industrial Injuries in the period 1 January 2010 to 31 March 2010. RESULTS: Three hundred and seventy individuals, 269 females and 101 males, with a mean age of 39.9 years, responded to the questionnaire (response rate of 73%). The overall percentage of correct answers was 73%. Variables significantly influencing the level of knowledge were sex and age, with a need for more information in males and in patients above the age of 50 years. No significant influence of level of education, eczema activity, previous information about HE, previous or current atopic eczema or dermatology life quality index (DLQI) was found. CONCLUSION: There is still potential for improvement of the level of knowledge among patients with occupational HE. Special attention should be paid to males and patients above the age of 50 years.

Health perspectives and handling of PFAS contamination in Denmark.

Per- and polyfluorinated alkyl substances (PFAS) are a group of man-made extremely persistent chemicals that have been spread worldwide since the 1950s due to their properties as effective water- and grease-repellent and heat- and temperature-resistant. They are associated with an increasing number of health effects including immune and hormonal disturbances and some types of cancer. We present a review of PFAS pollution in Denmark, the current human exposure, suspected health effects, and patient management in environmental medicine.

Occupational exposure and markers of genetic damage, systemic inflammation and lung function: a Danish cross-sectional study among air force personnel.

Air force ground crew personnel are potentially exposed to fuels and lubricants, as raw materials, vapours and combustion exhaust emissions, during operation and maintenance of aircrafts. This study investigated exposure levels and biomarkers of effects for employees at a Danish air force military base. We enrolled self-reported healthy and non-smoking employees (n = 79) and grouped them by exposure based on job function, considered to be potentially exposed (aircraft engineers, crew chiefs, fuel operators and munition specialists) or as reference group with minimal occupational exposure (avionics and office workers). We measured exposure levels to polycyclic aromatic hydrocarbons (PAHs) and organophosphate esters (OPEs) by silicone bands and skin wipes (PAHs only) as well as urinary excretion of PAH metabolites (OH-PAHs). Additionally, we assessed exposure levels of ultrafine particles (UFPs) in the breathing zone for specific job functions. As biomarkers of effect, we assessed lung function, plasma levels of acute phase inflammatory markers, and genetic damage levels in peripheral blood cells. Exposure levels of total PAHs, OPEs and OH-PAHs did not differ between exposure groups or job functions, with low correlations between PAHs in different matrices. Among the measured job functions, the UFP levels were higher for the crew chiefs. The exposure level of the PAH fluorene was significantly higher for the exposed group than the reference group (15.9 ± 23.7 ng/g per 24 h vs 5.28 ± 7.87 ng/g per 24 h, p = 0.007), as was the OPE triphenyl phosphate (305 ± 606 vs 19.7 ± 33.8 ng/g per 24 h, p = 0.011). The OPE tris(1,3-dichlor-2-propyl)phosphate had a higher mean in the exposed group (60.7 ± 135 ng/g per 24 h) compared to the reference group (8.89 ± 15.7 ng/g per 24 h) but did not reach significance. No evidence of effects for biomarkers of systemic inflammation, genetic damage or lung function was found. Overall, our biomonitoring study show limited evidence of occupational exposure of air force ground crew personnel to UFPs, PAHs and OPEs. Furthermore, the OH-PAHs and the assessed biomarkers of early biological effects did not differ between exposed and reference groups.