Risky listening behaviour to music via headphones and its determinants - 7.5 years OHRKAN cohort study.

OBJECTIVE: To examine risky leisure noise exposure from listening to music via headphones and to identify potential determinants with special focus on portable listening devices (PLDs) among adolescents over a period of 7.5-years. DESIGN: Data were collected by questionnaires at four equidistant time points (O1-O4). Music exposure via headphones was calculated based on self-reported volume setting and listening duration. Exceeding 85 dB(A) equivalent for a 40-hour working week was defined as risky noise exposure. Determinants of risky headphone and PLD exposure were investigated using generalised estimating equations and accounting for missing data by multiple imputation. STUDY SAMPLE: Closed cohort of 2148 students attending 9th grade of any secondary school type in Regensburg (Germany), during 2009 to 2011. RESULTS: Risky noise exposure from headphone usage was almost twice as high in wave O1 and O2 (at age 15 or 18) compared with 20-23-year-olds in O3 and O4. Risky exposure to headphones and PLDs were associated with younger age, low and medium education, single-parent household and smoking, whereas good self-rated hearing showed a protective effect. Additionally, not being born in Germany was associated with risky PLD exposure. CONCLUSION: Before harmful behaviours become entrenched, starting preventive efforts at a young age is essential.

The validity of using a self-report single question as a means to detect hearing loss in an adolescent population.

OBJECTIVE: The overall objective in the study was to compare self-reported hearing based on a single question ("how good would you currently rate your hearing?") to measure hearing loss determined by audiometry in a cohort of adolescents. Prevalence of audiometrically measured hearing loss and frequencies of self-reported poor hearing as well as factors that have an impact on self-reported hearing were examined. DESIGN: Baseline and 5-year follow-up data of the Ohrkan study were used. Participants filled in a questionnaire and underwent audiometric measurements. STUDY SAMPLE: Data from 979 adolescents were analysed. Participants were 54.7% female and aged between 13 and 18 years at baseline and 17-21 years at 5-yr follow-up. RESULTS: The single question on self-reported hearing ability achieved a sensitivity of 41.9% and a positive predictive value of 7.1% at baseline. For the 5-yr follow-up, sensitivity was 40.0%, positive predictive value was 13.9%. Factors influencing self-reported poor hearing were gender, tinnitus, "muffled" ears after exposure to loud noise (e.g. after a concert) and low-frequency hearing loss. CONCLUSIONS: The single question about hearing ability used in the Ohrkan study is not sufficient to replace audiometry to detect hearing loss as defined in the study in adolescents.

Ten-year results of leisure noise exposure among adolescents and young adults-findings from the OHRKAN cohort study.

OBJECTIVE: To observe total leisure noise (TLN) exposure and to investigate determinants of risky TLN exposure among adolescents and young adults over a ten-year observation period. DESIGN: OHRKAN is a longitudinal study with five equidistantly distributed questionnaires (waves) over ten years. Risky TLN exposure was defined as exceeding ≥85dB(A) averaged over 40h per week. To identify determinants of risky TLN exposure longitudinally, generalised estimating equations were applied. STUDY SAMPLE: A subgroup (n = 661; mean age 25.6 years in the fifth wave; 58.4% female) of the closed cohort study OHRKAN was analysed. Included participants took part in the fifth wave prior to the study break due to COVID-19. RESULTS: Analysis of participants' data from all five waves showed that risky TLN exposure was highest during the second wave (72.0%), when participants were aged 17-19 years, and thereafter steadily declined. Among young adults, attendance at discotheques and private parties, especially, caused very high exposure. Determinants of risky TLN exposure were wave time point, male gender, a higher level of education, and smoking. CONCLUSIONS: As TLN exposure is highest among older adolescents, prevention programs should target younger teenagers and be tailored to the identified risk groups. The risk from private parties should be addressed.

Mental health and work-related factors in healthcare workers in a pandemic - meta-analysis.

Due to the SARS-CoV-2 pandemic, healthcare workers worldwide faced major challenges in the form of psychological stress. The aim of this systematic literature review and meta-analysis is to identify mental health consequences and associated work-related factors in healthcare workers during a pandemic and to quantify the influence of associated work-related factors on mental health consequences. A systematic literature search according to PRISMA was conducted on 5 August 2021 using the databases PubMed Central and APA PsychInfo. The included studies investigated the mental health consequences and associated work-related factors in healthcare workers in a pandemic. In addition, we performed a risk of bias analysis to assess the study quality of the included studies using the JBI checklists. Random-effect models and pooled effect estimators were used for the meta-analysis. The Chi2 and I2 statistics were used to identify the statistical heterogeneity. Additional sensitivity analysis was performed. From a total of 3,910 publications, 43 studies met the inclusion criteria. These studies provided 15 stress consequences and 20 stress factors. The most frequently reported stress factors were 'contact with COVID-19 patients', 'no education or training in handling infectious diseases' and 'insufficient protective equipment'. Anxiety, stress, and depression were the most common outcomes identified. Analyses showed an increase in anxiety scores among HCWs who cared for COVID-19 patients, as well as a rise in depressive symptoms due to inadequate or no personal protective equipment. In this review, various pandemic-associated stress factors and stress consequences of healthcare workers were observed. With the results, criteria for effective measures and interventions can be developed to minimize the risk of stress consequences.

Exposure to leisure noise and intermittent tinnitus among young adults in Bavaria: longitudinal data from a prospective cohort study.

OBJECTIVES: To investigate the association between total leisure noise exposure and intermittent tinnitus among young adults. DESIGN: Data were obtained from the Ohrkan study, an ongoing prospective cohort study conducted in South Germany since 2009. Information about exposure to impulse and leisure noise, tinnitus occurrences, sociodemographic variables, and self-rated hearing ability were analysed at four time points over a period of seven and a half years. STUDY SAMPLE: Participants of the Ohrkan cohort study, who provided data about the occurrence of tinnitus for all surveys (n = 1028). RESULTS: Intermittent tinnitus was reported in the majority of the sample (60%). The risk for intermittent tinnitus increased with higher sound pressure levels from exposure to leisure noise (full model (Odds Ratio, 95%CI): 80-<85dB(A): 1.41 [1.13-1.78], 85-<90dB(A): 1.73 [1.38-2.16], >90dB(A): 2.04 [1.59-2.61]). Visiting nightclubs was a major contributor to this relationship. Of the considered covariables, self-rated hearing as "poor", and growing up in a single-parent household were significantly associated with intermittent tinnitus. CONCLUSION: Intermittent tinnitus is very frequent among young adults and is associated with high levels of leisure noise exposure. To prevent intermittent tinnitus, reduced sound pressure levels and the use of hearing protection are necessary.

Compensating for missing data in the OHRKAN cohort study examining total leisure noise exposure among adolescents.

OBJECTIVE: Investigating determinants of total leisure noise (TLN) exposure among adolescents over 7.5 years and compensating for missing data due to loss to follow-up. DESIGN: In the OHRKAN cohort study, data were collected by questionnaires at four waves. TLN was calculated from self-reported duration spent participating in 18 leisure activities. High exposure was defined as exceeding 85 dB(A) of equivalent continuous average sound pressure level (SPL) during a 40-h week. Multiple imputation (MI) and generalised estimating equations (GEE) were used to analyse odds ratios (OR) of determinants of TLN exposure and compared to complete-case analysis. STUDY SAMPLE: Closed cohort of 2148 students enrolled in grade 9 of any school in Regensburg (Germany), recruited from 2009 to 2011. RESULTS: Up to 74% of adolescents had risky TLN exposure, depending on wave. The most significant sources were discotheques, portable listening devices (PLD) and stereo systems. Higher TLN exposure was associated with time point, education, single-parent households and gender. MI under MAR assumption changed results only slightly compared to complete-case analysis. CONCLUSIONS: Prevalence of risky TLN is high during adolescence. MI reinforced trends detected in former results of OHRKAN. Preventive measures should consider the main drivers of noise exposure including changes by age and high risks groups.

[Predictors of Adolescents' Willingness to Participate in Long-term Studies: Results of the Ohrkan Cohort Study on Leisure Time Noise Exposure]. / Prädiktoren der Teilnahmebereitschaft von Jugendlichen in Langzeitstudien: Ergebnisse der Ohrkan Kohortenstudie zur Freizeitlärmexposition.

BACKGROUND AND AIM OF THE STUDY: The loss of participants during the follow-up of cohort studies can introduce bias if persons who leave the study differ from those who continue to participate over time. Many studies have investigated socio-demographic and health factors associated with participation/non-participation in epidemiological studies. However, relatively few studies are available for school-based cohorts. The aim of this study was to determine predictors of willingness to participate in the Ohrkan study, an ongoing longitudinal survey of adolescents that collects detailed information on leisure time noise exposure and potential effects on hearing. METHODS: Using the Ohrkan cohort of 2,148 persons recruited in 2009-2011 (O-I) among the ninth graders of any secondary school type in Regensburg and followed-up in 2012-14 (O-II) and 2015-16 (O-III). RESULTS: The probability of participating in O-II and O-III was higher for persons without a migration background, who attended university-preparatory secondary school at baseline and whose parents had a higher educational level or lived together. Persons who had not changed their place of residence in the last 2.5 years also participated 3 times as often as respondents who moved inside or outside of Regensburg. CONCLUSION: The knowledge of determinants of attrition and retention makes it easier to specify which groups of a cohort are most likely to be lost to follow-up. These groups can be targeted in order to minimize their loss in the future follow-ups. Moreover, the predictors can be used in statistical missing data techniques such as multiple imputation.

Longitudinal analysis of leisure noise exposure among adolescents with special focus on portable listening devices: the OHRKAN cohort study.

The aim was to investigate leisure noise exposure and sociodemographic determinants of risky leisure noise exposure over five years in 2148 students visiting grade 9 of any school type in a German city from 2009-2011. Within the OHRKAN cohort study, leisure noise exposure was calculated from literature-retrieved sound pressure levels (SPLs) and self-reported duration of 18 leisure activities at baseline and two follow-ups. Risky exposure was defined as exceeding 85 dB(A) averaged over a 40-h-week. Determinants of risky total leisure noise (TLN) exposure and risky exposure to portable listening devices (PLDs) were investigated using generalised estimating equations (GEEs). Up to 73% of students exceeded noise levels of 85 dB(A) at some timepoint. The noise exposure and importance of different leisure activities changed with increasing age. Risky exposure to TLN and PLDs was associated with lower education, single parent households and being male. Risky PLD exposure was additionally associated with a migrant background. Current prevention measures for leisure noise exposure must be extended to at-risk groups. Besides enhancing campaigns in lower education schools, acoustical insulation in sports halls, noise warnings on tools or in videogames could address especially men. Migrants need education about healthy PLD use in their native language if necessary.

[Exposure of Adolescents to Leisure-Time Noise: Results of the First Follow-Up of the Ohrkan Cohort Study]. / Belastung mit Freizeitlärm unter jungen Erwachsenen: Ergebnisse des ersten Follow-Up der Ohrkan-Kohortenstudie.

OBJECTIVE: Analysis of changes in leisure noise exposure among adolescents during 2.5 years of follow-up. METHODS: The analysis is based on the Ohrkan cohort study. A total of 2 149 9th graders in the City of Regensburg (mostly aged 15-16 years) were recruited between 2009-2011. At 2.5-year follow-up, the participants were asked again about leisure noise exposure. Both at baseline (O-I) and in the follow-up (O-II), self-reported frequency of participation in noisy activities was combined with literature-based values of usual sound levels to calculate the total weekly noise exposure. This exposure was compared to the lower exposure action value (lEAV) of 80 dB(A) given by the occupational health and safety regulations. Logistic regression was used to determine the factors associated with leisure noise exposure above the lEAV. RESULTS: Exposure data from both time points were available for 1 704 adolescents (54% female). The percentage of participants who were exposed to leisure noise exceeding the lEAV increased from 75 to 92% due to more persons visiting discotheques in O-II. In both surveys, the activity reported by the highest percentage of participants and with the longest exposure duration was listening to pop music via portable listening devices (PLD) although the proportion of users decreased slightly. Not being a pupil affected PLD use at volume levels >80 dB (A) whereas older age was associated with noise exposure in discotheques. CONCLUSIONS: O-II shows that adolescents are engaged in leisure activities under harmful noise levels and that noise exposure sources are changing with age. These issues should be considered in the developing of prevention programs.

Audiometric notch and extended high-frequency hearing threshold shift in relation to total leisure noise exposure: An exploratory analysis.

BACKGROUND: Studies investigating leisure noise effect on extended high frequency hearing are insufficient and they have inconsistent results. The aim of this study was to investigate if extended high-frequency hearing threshold shift is related to audiometric notch, and if total leisure noise exposure is associated with extended high-frequency hearing threshold shift. MATERIALS AND METHODS: A questionnaire of the Ohrkan cohort study was used to collect information on demographics and leisure time activities. Conventional and extended high-frequency audiometry was performed. We did logistic regression between extended high-frequency hearing threshold shift and audiometric notch as well as between total leisure noise exposure and extended high-frequency hearing threshold shift. Potential confounders (sex, school type, and firecrackers) were included. RESULTS: Data from 278 participants (aged 18-23 years, 53.2% female) were analyzed. Associations between hearing threshold shift at 10, 11.2, 12.5, and 14 kHz with audiometric notch were observed with a higher prevalence of threshold shift at the four frequencies, compared to the notch. However, we found no associations between total leisure noise exposure and hearing threshold shift at any extended high frequency. CONCLUSION: This exploratory analysis suggests that while extended high-frequency hearing threshold shifts are not related to total leisure noise exposure, they are strongly associated with audiometric notch. This leads us to further explore the hypothesis that extended high-frequency threshold shift might be indicative of the appearance of audiometric notch at a later time point, which can be investigated in the future follow-ups of the Ohrkan cohort.

Human biomonitoring follow-up study on PFOA contamination and investigation of possible influencing factors on PFOA exposure in a German population originally exposed to emissions from a fluoropolymer production plant.

BACKGROUND: In the past, perfluorooctanoic acid (PFOA) was produced and applied as an emulsifier in a fluoropolymer production plant in the Altötting district, southern Bavaria (Germany). This chemical was released directly into the environment, resulting in the contamination of the local drinking water. During a human biomonitoring (HBM) survey in 2018, increased median PFOA blood serum levels, compared to a normally exposed control group with no known source of PFOA exposure from Munich, Germany, were detected in the resident population (23.18 µg/l in the general population, 20.71 µg/l in the children's group). The follow-up study aimed to investigate whether purification of the drinking water as the main PFOA exposure source has been successful in reducing internal PFOA exposure and to estimate the association of internal PFOA exposure with possible influencing factors. METHODS: Only individuals who had already participated in the HBM study in 2018 were included. For the determination of the PFOA serum concentration, 5 ml of blood was drawn from each participating person. Blood samples were collected in the period from June to August 2022. Furthermore, information on sociodemographic characteristics, health status, dietary behaviour and other lifestyle factors were collected by means of a self-administered questionnaire. To examine the association of PFOA blood serum levels with possible influencing factors, such as age, gender and consumption of fish and game meat, a logistic regression model with a PFOA value > 10 µg/l as outcome was used. RESULTS: A total of 764 individuals participated in the follow-up study in 2022. Analyses were performed separately for the general population (n = 559), women of reproductive age (15-49 years old) (n = 120), and children under 12 years old (n = 30). Median PFOA blood levels have decreased by 56.9% in the general population, by 59.8% in the group of women of reproductive age and by 73.4% in the group of children under 12 years old. In the general population, a higher probability of a PFOA value > 10 µg/l was found for those aged 40-59 years (Odds ratio (OR) = 2.33 (95%CI: 1.23 to 4.43, p = 0.01) and those aged 60 years and older (OR = 5.32, 95%CI: 2.78 to 10.19, p < 0.001). CONCLUSIONS: In all study groups, the median PFOA serum levels decreased as expected after a half-life of four years, which confirms that contamination via drinking water has ceased. Furthermore, our study identified age as a significant predictor of internal PFOA exposure, while no influence was found for the consumption of fish and game meat. Further investigations are needed to quantify in a more detailed way the influence of dietary habits on PFOA exposure.

The Relevance of Leisure Noise to Hearing Threshold Shifts: A Longitudinal Analysis Among Adolescents.

PURPOSE: The aim of this study was to analyze the association of total leisure noise exposure and hearing threshold shifts over 5 years among adolescents enrolled in the Ohrkan cohort study. METHOD: The Ohrkan cohort of 2,148 students aged 13-19 years was recruited from 2009 to 2011 and followed up 5 years later. Complete baseline and follow-up reports on exposure and outcome were available for 989 participants. Leisure noise exposure was assessed by questionnaires, and clinical audiometric examinations were performed. Two outcomes were defined: occurrence of the Niskar notch pattern and audiometry showing maximum hearing threshold values at 3, 4, and 6 kHz (both ears). Longitudinal analysis using generalized estimating equations was performed. RESULTS: High total leisure noise exposure, defined as an energy equivalent of a 40-hr week of > 85 dBA, was estimated for 32.7% of students at baseline and 63.8% at follow-up. A noise notch was observed in 1.1% of adolescents at baseline and 3.3% at follow-up. At baseline, the maximum measured threshold shift was 55 dB, which increased to 85 dB at the follow-up. Longitudinal analysis did not reveal an association between leisure noise exposure and hearing thresholds. Hearing threshold shifts or noise notches were associated with sex, school type, and time point of measurement. CONCLUSIONS: No relationship was found between leisure noise and hearing thresholds. Male adolescents and those attending secondary general schools, with graduation following completion of ninth or 10th grade, had a greater likelihood of developing hearing threshold shifts. Prevention programs should focus on these risk groups. SUPPLEMENTAL MATERIAL: https://doi.org/10.23641/asha.19233462.

A systematic review of experimental animal studies on microbial bioaerosols: Dose-response data for the derivation of exposure limits.

Although exposure to high levels of microbial bioaerosols can be linked to the deterioration of the human respiratory system, precise exposure levels responsible for such effects are still unknown. A previous systematic review concluded that there was not enough information in the studies in humans to derive an exposure-response relationship. Thus, the aim of this systematic review was to derive exposure limits for microbial bioaerosols based on health effects in experimental animal studies. A systematic search was done in MEDLINE (PubMed) for long-term in vivo exposure of the respiratory system via inhalation of a quantified microbial bioaerosol. A total of n = 301 studies were retrieved. Abstract screening using predefined inclusion and exclusion criteria was followed by full-text screening and standardized data extraction of study characteristics and measured outcomes. As a result, four suitable studies were identified where mice or guinea pigs were exposed for 4-12 weeks to a previously described mixture of fungal spores or conidia via inhalation. The number of macrophages, neutrophils, eosinophils and lymphocytes following subchronic exposure has been reported by all included papers and suggested a dose- and time-dependent relationship. Significant inflammation was observed following subacute exposure to Aspergillus fumigatus. However, the outcomes of the studies could not be directly compared due to the large degree of variation and poor description of the exposure conditions. It is our conclusion that more experimental research needs to be done with the specific aim of establishing a No-Observed-Adverse-Effect Level (NOAEL) and a Lowest-Observed-Adverse-Effect Level (LOAEL) for exposure to microbial bioaerosols in ambient air. Expertise of both exposure and outcome assessment should be brought together to enable standardization of experimental animal studies with properly generated aerosols aiming to derive health-based exposure limits.

Evaluation of exposure-response relationships for health effects of microbial bioaerosols - A systematic review.

Studies suggest adverse health effects following exposure to bioaerosols in the environment and in particular at workplaces. However, there is still a lack of health-related exposure limits based on toxicological or epidemiological studies from environmental health or from the working environment. The aim of this study was to derive health-based exposure limits for bioaerosols that can protect the general population as group "at risk" via environmental exposure using analysis of peer-reviewed studies related to occupational medicine, indoor air and environmental health. The derivation of exposure limits should be conducted by the members of a bioaerosol expert panel according to established toxicological criteria. A systematic review was performed in Medline (PubMed) including studies containing both data on exposure measurements and observed health outcomes. In addition, literature recommended by the experts was considered. A comprehensive search strategy was generated and resulted in a total of n=1569 studies in combination with the literature recommendations. Subsequently, abstracts were screened using defined exclusion criteria yielding a final number of n=44 studies. A standardized extraction sheet was used to combine data on health effects and exposure to different bioaerosols. After full-text screening and extraction according to the defined exclusion criteria n=20 studies were selected all related to occupational exposures comprising the working areas wood processing, farming, waste processing and others. These studies were analyzed in collaboration with the bioaerosol expert network in terms of suitability for derivation of health-related exposure limits. The bioaerosol expert network concluded that none of the analyzed studies provided suitable dose-response relationships for derivation of exposure limits. The main reasons were: (1) lack of studies with valid dose-response data; (2) diversity of employed measuring methods for microorganisms and bioaerosol-emitting facilities; (3) heterogeneity of health effects; (4) insufficient exposure assessment. However, several indicator parameters and exposure concentrations could be identified for different bioaerosol-emitting facilities. Nevertheless, health-related exposure limits are urgently needed especially in approval procedures of facilities like composting plants or livestock farms emitting bioaerosols in the neighbourhood of residents. In the regulatory toxicology framework, it is common to use animal experimental studies for derivation of general exposure limits if appropriate environmental epidemiological studies on harmful substances are lacking. This might be another possibility to obtain health-related exposure limits for specific bioaerosol parameters. Furthermore, we recommend to use suitable measurable outcome parameters related to bioaerosols; to measure bioaerosols according to a protocol representative for exposure pattern and duration at the particular work place; to develop standardized detection methods for indicator parameters; to combine different detection methods to compensate for the limitations of each method; to apply new analysis methods to identify the real risk potential.

Assessing the environmental health relevance of cooling towers--a systematic review of legionellosis outbreaks.

Bioaerosols from cooling towers are often suspected to cause community-acquired legionellosis outbreaks. Although Legionella infections can mostly be assigned to the emission sources, uncertainty exists about the release and distribution into the air, the occurrence of the respirable virulent form and the level of the infective concentration. Our study aimed to evaluate studies on legionellosis outbreaks attributed to cooling towers published within the last 11 years by means of a systematic review of the literature. 19 legionellosis outbreaks were identified affecting 12 countries. Recurring events were observed in Spain and Great Britain. In total, 1609 confirmed cases of legionellosis and a case-fatality rate of approximately 6% were reported. Duration of outbreaks was 65 days on average. For diagnosis the urinary antigen test was mainly used. Age, smoking, male sex and underlying diseases (diabetes, immunodeficiency) could be confirmed as risk factors. Smoking and underlying diseases were the most frequent risk factors associated with legionellosis in 11 and 10 of the 19 studies, respectively. The meteorological conditions varied strongly. Several studies reported a temporal association of outbreaks with inadequate maintenance of the cooling systems. A match of clinical and environmental isolates by serotyping and/or molecular subtyping could be confirmed in 84% of outbreaks. Legionella-contaminated cooling towers as environmental trigger, in particular in the neighbourhood of susceptible individuals, can cause severe health problems and even death. To prevent and control Legionella contamination of cooling towers, maintenance actions should focus on low-emission cleaning procedures of cooling towers combined with control measurements of water and air samples. Procedures allowing rapid detection and risk assessment in the case of outbreaks are essential for adequate public health measures. Systematic registration of cooling towers will facilitate the identification of the source of outbreaks and help to shorten their duration.