Shoulder Tendinopathies and Occupational Biomechanical Overload: A Critical Appraisal of Available Evidence.

BACKGROUND: The aim of this study is to evaluate the association between occupational exposure to biomechanical risk factors and shoulder tendinopathies. METHODS: We updated recent systematic reviews about specific shoulder disorders and work-related risk factors. MEDLINE was searched up to September 2022. Studies satisfying the following criteria were included: i) the diagnosis was based on physical examination plus imaging data (when available), and ii) the exposure assessment was based on video analysis and/or directly measured. RESULTS: Five studies met the inclusion criteria: three cross-sectional studies identified from published systematic reviews and two cohort studies retrieved from the update. Two studies investigated shoulder tendinitis, one supraspinatus tendinitis, and the other two rotator cuff syndrome. The diagnosis was based on physical examination, not supported by imaging techniques for all the included studies. In four out of five studies, the exposure was assessed by experienced ergonomists with the support of video recordings. In two studies, the exposure assessment was further supplemented by force gauge measurements or direct measurements of upper arm elevation. Only the combined exposure of working with arms above shoulder level with forceful hand exertion appears to be associated with rotator cuff syndrome: i) a cohort study reported an HR=1.11 (95%CI 1.01-1.22) for each unit increase in forceful repetition rate when the upper arm is flexed ≥45° for ≥29% of the working time; and ii) a cross-sectional study showed an OR=2.43 (95%CI 1.04-5.68) for the combination of upper arm flexion ≥45° for more than 15% of the time with a duty cycle of forceful exertions more than 9% of the time. CONCLUSIONS: There is moderate evidence of a causal association between shoulder tendinopathy and combined exposures of working above shoulder level with forceful hand exertion. The evidence is insufficient for any single biomechanical exposure on its own. High-quality cohort studies with direct exposure measures and objective diagnostic criteria are needed. The occupational origin of shoulder tendinopathies is still an open question that must be properly answered.

Quantitative Assessment of Asbestos Fibers in Abdominal Organs: A Scoping Review.

BACKGROUND: Quantification of asbestos fibers has been mainly performed in the lung but rarely in other organs. However, this may be relevant to understanding better translocation pathways and the oncogenic effects of asbestos on the human body. Electron microscopy is the best technology available to assess the type of fiber, dimensions, and distribution of asbestos fibers in different tissues and as a biomarker of cumulative dose. OBJECTIVES: This scoping review aims to summarize the findings of the studies in which asbestos fibers have been quantified by electron microscopy, occasionally associated with X-ray microanalysis, in normal and pathological tissue of ten abdominal organs. METHODS: A scoping review has been performed by searching articles that quantified asbestos fibers in abdominal organs by electron microscopy (Scanning- SEM or Transmission- TEM). RESULTS: The 12 selected studies included 204 cases, and 325 samples were analyzed. The colon and rectum, kidney, bladder, and abdominal lymph nodes were the organs with at least ten samples available with quantification of asbestos fibers. Asbestos fibers were detected in all the abdominal organs considered: the highest value (152,32 million fibers per gram of dry tissue) was found in the colon and was identified using STEM with EDS. CONCLUSION: The studies included were heterogeneous in terms of exposure and cases, type of samples, as well as analytical techniques, therefore we cannot confirm a specific pattern of distribution in any organ, based on the low homogeneity of the exposure status. The colon is the organ in which the number of fibers is the highest, probably because of exposure arising from both internal distribution of inhaled fibers and ingestion. Additional studies of the number of asbestos fibers in abdominal organs should be made to achieve better representativity.

Mortality from suicide among agricultural, fishery, forestry and hunting workers in Italy and the contribution of work-related factors.

OBJECTIVES: Excess risk of suicide has been reported among workers in agriculture, fishery, forestry and hunting (AFFH). However, there is still uncertainty in the quantification of the risk and in the contribution of work-related factors. We aimed to quantify the suicide mortality risk among these workers in Italy. METHODS: We carried out a historical cohort study based on record linkage between the 2011 Italian census and the mortality archives for years 2012-2017. The mortality rate ratio (MRR) was used as a measure of risk. MRR was estimated through quasi-Poisson regression models using workers in other sectors as reference category. Models were adjusted for age, citizenship, marital status, area of residence, education, employment status and hours worked per week. RESULTS: The cohort included 1 004 655 workers employed in the AFFH sector and 15 269 181 workers in other sectors. During the 6-year follow-up, 559 deaths from suicide (500 men and 59 women) occurred among AFFH workers and 5917 (4935 men and 982 women) among workers in other sectors. The MRR for suicide was 1.36 (95% CI 1.19 to 1.55) among men and 1.18 (95% CI 0.87 to 1.60) among women. The excess risk was remarkably high for casual and fixed-term contract workers (3.01, 95% CI 1.50 to 6.04). CONCLUSIONS: Male workers in AFFH are at high risk of suicide mortality, and casual and fixed-term contract workers are at exceedingly high risk. Our study also suggests a higher risk among single, highly educated and long-hours workers. Female workers in AFFH do not have an appreciably increased risk.

Criteria for diagnosis and attribution of an occupational musculoskeletal disease.

BACKGROUND: Criteria for diagnosis and compensation of occupational musculoskeletal diseases varies widely between countries as demonstrated by the large differences between countries with comparable economics and social systems (for example, within the European Union). Several countries have a list of occupational diseases and sometimes these lists include diagnostic and attribution criteria, but these criteria are usually not very specific, and they may also be very different. OBJECTIVES: The aim of this paper is to explicitly define what are the information needed for an evidence-based diagnosis and attribution of an occupational musculoskeletal disease. METHODS: Based on the general framework of evidence-based medicine, a review is presented of the information required to define: - when a musculoskeletal disease is present, according to the best available techniques; - how to define a relevant exposure to biomechanical risk factors, according to the best available techniques. RESULTS: Criteria are presented to combine information regarding the diagnosis of a musculoskeletal disease and exposure to biomechanical risk factors for an evidence-based attribution of the disease to the occupational exposure. The criteria use a probabilistic model that combine epidemiologic and medical findings, workplace exposure assessment, and non-occupational factors evaluation. DISCUSSION: The use of the proposed criteria may improve the process of diagnosis and attribution of an occupational musculoskeletal disease. In addition, it makes possible to associate a probability rank to the attribution and, ultimately, it may improve the overall quality of the decisional process of the occupational physician.

Surgical masks vs respirators for the protection against coronavirus infection: state of the art.

BACKGROUND: During the Covid-19 outbreak, a recurrent subject in scientific literature has been brought back into discussion: whether surgical masks provide a sufficient protection against airborne SARS-CoV-2 infections. OBJECTIVES: The objective of this review is to summarize the available studies which have compared the respective effectiveness of surgical masks and filtering facepiece respirators  for the prevention of infections caused by viruses that are transmitted by the respiratory tract. METHODS: The relevant scientific literature was identified by querying the PubMed database with a combination of search strings. The narrower search string "(surgical mask *) AND (respirator OR respirators)" included all the relevant articles retrieved using broader search strategies. Of all the relevant articles found, seven systematic reviews were selected and examined. RESULTS: The currently available scientific evidence seems to suggest that surgical masks and N95 respirators/FFP2 confer an equivalent degree of protection against airborne viral infections. DISCUSSION: Since surgical masks are less expensive than N95 respirators but seem to be as effective in protecting against airborne infection and they are also more comfortable for the user, requiring less respiratory work, they should be the standard protective device for health care workers and especially for workers who carry out non-medical jobs. Filtering facepiece respirators, whose extended use is less comfortable for the wearer, may be preferred for procedures which require greater protection for a shorter time.

[Occupational safety and health risks in seaport: an update of narrative review]. / I rischi per la salute e la sicurezza nel lavoro portuale: aggiornamento della revisione narrativa della letteratura.

SUMMARY: Seaports are complex systems in which workers can be exposed to a large variety of safety and health risks. Nevertheless, a little literature is available concerning this topic, if we exclude the specific area of shipbuilding industry. Objectives. The aim of this paper is to update the review of the scientific literature previously published as result of a project concerning the occupational risks in seaports. Methods. Literature on this theme, obtained consulting the main databases (PubMed, Scholar and CCOHS) from 2012 and up to April 2019, was reviewed. Results. 5 of 8 articles published after 2012 were related to risk of release or formation of volatile compounds in restricted and poorly ventilated areas or inhalation of particles from specific goods. Three papers specifically debated musculoskeletal disorders related to loading/unloading procedures, occupational diseases and injuries. Conclusions. The update of the literature highlighted intrinsically dangerous goods, toxic volatile compounds and emissions as critical aspects of seaport activities related to goods handling. Recently, the literature shows a growing interest in occupational health, especially work-related musculoskeletal diseases. Prevention measures and implementation of worker's training and information are identified by all authors as the more effective action to increase health and safety..

Position Paper on Asbestos of the Italian Society of Occupational Medicine.

The Position Paper (PP) on asbestos of the Italian Society of Occupational Medicine (SIML) aims at providing a tool to the occupational physician to address current diagnostic criteria and results of epidemiological studies, and their consequences in terms of preventive and evaluation actions for insurance, compensation and litigation. The PP was based on an extensive review of the scientific literature and was compiled by a Working Group comprising researchers who have contributed to the international literature on asbestos-related diseases, as well as occupational physicians with extensive experience in the evaluation of risks and the medical surveillance of workers currently and formerly exposed to asbestos. The PP was drafted and reviewed between 2017 and 2018; its final version was prepared according to the guidelines of AGREE Reporting Checklist. All the members of the Working Group subscribed to the document, which was eventually approved by SIML's Executive Committee. The first section addresses industrial hygiene issues, such as methods for environmental monitoring, advantages and limitations of different microscopy techniques, the potential role of microfibers and approaches for retrospective assessment of exposure, in particular in epidemiological studies. The second section reviews the biological effects of asbestos with particular attention to the diagnostic aspects of asbestosis, pleural changes, mesothelioma and lung cancer. In the following section the criteria of causal attribution are discussed, together with different hypotheses on the form of the risk functions, with a comparison of the opinions prevalent in the literature. In particular, the models of the risk function for mesothelioma were examined, in the light of the hypothesis of an acceleration or anticipation of the events in relation to the dose. The last section discusses topics of immediate relevance for the occupational physician, such as health surveillance of former exposed and of workers currently exposed in remediation activities.

Occupational exposure to asbestos and risk of cholangiocarcinoma: a population-based case-control study in four Nordic countries.

OBJECTIVES: To assess the association between occupational exposure to asbestos and the risk of cholangiocarcinoma (CC). METHODS: We conducted a case-control study nested in the Nordic Occupational Cancer (NOCCA) cohort. We studied 1458 intrahepatic CC (ICC) and 3972 extrahepatic CC (ECC) cases occurring among subjects born in 1920 or later in Finland, Iceland, Norway and Sweden. Each case was individually matched by birth year, gender and country to five population controls. The cumulative exposure to asbestos (measured in fibres (f)/ml × years) was assessed by applying the NOCCA job-exposure matrix to data on occupations collected during national population censuses (conducted in 1960, 1970, 1980/81 and 1990). Odds ratios (OR) and 95% CI were estimated using conditional logistic regression models adjusted by printing industry work. RESULTS: We observed an increasing risk of ICC with cumulative exposure to asbestos: never exposed, OR 1.0 (reference category); 0.1-4.9 f/mL × years, OR 1.1 (95% CI 0.9 to 1.3); 5.0-9.9 f/mL × years, OR 1.3 (95% CI 0.9 to 2.1); 10.0-14.9 f/mL × years, OR 1.6 (95% CI 1.0 to 2.5); ≥15.0 f/mL × years, OR 1.7 (95% CI 1.1 to 2.6). We did not observe an association between cumulative asbestos exposure and ECC. CONCLUSIONS: Our study provides evidence that exposure to asbestos might be a risk factor for ICC. Our findings also suggest that the association between ECC and asbestos is null or weaker than that observed for ICC. Further studies based on large industrial cohorts of asbestos workers and possibly accounting for personal characteristics and clinical history are needed.

Global Postural Reeducation in patients with chronic nonspecific neck pain: cross-over analysis of a randomized controlled trial.

OBJECTIVE: To compare the effects of Global Postural Reeducation (GPR) with Manual Therapy (MT) in participants with chronic nonspecific neck pain (NP). METHODS: Pre- and post-treatment analysis of cross-over data from an RCT was done. Seventy-eight subjects with chronic nonspecific NP aged 18 to 80 years completed the trial. The group who had received GPR crossed-over to MT and the previous MT group received GPR for 9 sessions once or twice a week. Measures were assessed at pre-treatment and post-treatment. Outcome measures included pain intensity [Visual Analogue Scale (VAS)], disability (Neck Disability Index), cervical Range of Motion (ROM), and kinesiophobia [Tampa Scale of Kinesiophobia (TSK)]. RESULTS: GPR targeted to crossed-over participants produced greater improvements in pain [Diff=-8.6; 95%CI=(-13.3; -3.8)], disability [Diff=-1.5; 95%CI=-2.8; -0.1], kinesiophobia [Diff=-1.8; 95%CI=(-3.2; -0.3)], and flexion/extension neck ROM [Diff=5.6; 95%CI=(1.8; 9.3)] at post-treatment compared to the MT group. When evaluating clinical improvement, by means of Minimal Clinically Important Differences, we found that GPR relevantly reduced neck disability with respect to MT [OR=2.13; 95% CI=(1.05; 4.35)], whereas the improvement of pain did not differ between groups [OR=1.84; 95%CI=0.85; 3.99)]. CONCLUSIONS: These results within the crossed-over group confirm previous findings from an RCT with the same sample. Sequence of treatment (GPR-to-MT vs MT-to-GPR) does not seem to weaken the greater effects of GPR compared to MT approach for chronic NP. Our findings suggest that GPR can induce hypoalgesic effects, reduce disability and kinesiophobia, and improve flexion/extension in neck ROM.

How job demands affect absenteeism? The mediating role of work-family conflict and exhaustion.

PURPOSE: To investigate how psychosocial factors (such as job demands and work-family conflict) produce absenteeism in the workplace, using the health impairment process of the job demands-resources model. According to this model, job demands lead to burnout (often measured with the emotional exhaustion component), which in turn could lead to outcomes (such as absenteeism). Work-family conflict (WFC) was also studied, because of contradictory results collected in the existing literature on absenteeism in the workplace, regarding the role of WFC in causing absenteeism. METHODS: Data were collected on 245 workers using both subjective (questionnaire on psychological risk factors and work-related health) and objective data (sickness leave frequency records). To test the hypothesis that job demands and WFC contribute to absenteeism in the workplace, a subsequent mediation analysis was used, which analysed both (a) the subsequent mediation of WFC and emotional exhaustion and (b) the separate roles played by the mediators proposed (WFC and emotional exhaustion). RESULTS: Job demands affect absenteeism through the subsequent mediation of WFC and emotional exhaustion. In addition, emotional exhaustion mediates the relationship between job demands and absenteeism, while WFC does not. CONCLUSION: In conclusion, subsequent mediation highlights the role of emotional exhaustion in causing absenteeism; in fact, when emotional exhaustion is included in the analysis, job demands are associated with higher levels of absenteeism. The results of this study suggest that without the concurrent contribution of emotional exhaustion, WFC does not influence absenteeism in the workplace. Our findings are useful for organizations that aim to reduce absenteeism.

Using PubMed search strings for efficient retrieval of manual therapy research literature.

OBJECTIVE: The aim of this study was to construct PubMed search strings that could efficiently retrieve studies on manual therapy (MT), especially for time-constrained clinicians. METHODS: Our experts chose 11 Medical Subject Heading terms describing MT along with 84 additional potential terms. For each term that was able to retrieve more than 100 abstracts, we systematically extracted a sample of abstracts from which we estimated the proportion of studies potentially relevant to MT. We then constructed 2 search strings: 1 narrow (threshold of pertinent articles ≥40%) and 1 expanded (including all terms for which a proportion had been calculated). We tested these search strings against articles on 2 conditions relevant to MT (thoracic and temporomandibular pain). We calculated the number of abstracts needed to read (NNR) to identify 1 potentially pertinent article in the context of these conditions. Finally, we evaluated the efficiency of the proposed PubMed search strings to identify relevant articles included in a systematic review on spinal manipulative therapy for chronic low back pain. RESULTS: Fifty-five search terms were able to extract more than 100 citations. The NNR to find 1 potentially pertinent article using the narrow string was 1.2 for thoracic pain and 1.3 for temporomandibular pain, and the NNR for the expanded string was 1.9 and 1.6, respectively. The narrow search strategy retrieved all the randomized controlled trials included in the systematic review selected for comparison. CONCLUSION: The proposed PubMed search strings may help health care professionals locate potentially pertinent articles and review a large number of MT studies efficiently to better implement evidence-based practice.

The Italian version of the Physical Therapy Patient Satisfaction Questionnaire - [PTPSQ-I(15)]: psychometric properties in a sample of inpatients.

BACKGROUND: In a previous study we described the translation, cultural adaptation, and validation of the Italian version of the PTPSQ [PTPSQ-I(15)] in outpatients. To the authors' knowledge, the PTPSQ was never studied in a hospital setting.The aims of this study were: (1) to establish the psychometric properties of the Physical Therapy Patient Satisfaction Questionnaire [PTPSQ- I(15)] in a sample of Italian inpatients, and (2) to investigate the relationships between the characteristics of patients and physical therapists and the indicators of satisfaction. METHODS: The PTPSQ-I(15) was administered to inpatients in a Physical Medicine and Rehabilitation Unit. Reliability of the PTPSQ-I(15) was measured by internal consistency (Cronbach's α) and test-retest stability (ICC 3,1). The internal structure was investigated by factor analysis. Divergent validity was measured by comparing the PTPSQ-I(15) with a Visual Analogue Scale (VAS) for pain and with a 5-point Likert-type scale evaluating the Global Perceived Effect (GPE) of the physical therapy treatment. RESULTS: The PTPSQ-I(15) was administered to 148 inpatients, and 73 completed a second administration. The PTPSQ-I(15) showed high internal consistency (α = 0.949) and test-retest stability (ICC = 0.996). Divergent validity was moderate for the GPE (r = - 0.502, P < 0.001) and strong for the VAS (r = -0.17, P = 0.07). Factor analysis showed a one-factor structure. CONCLUSIONS: The administration of PTPSQ-I(15) to inpatients demonstrated strong psychometric properties and its use can be recommended with Italian-speaking population. Further studies are suggested on the concurrent validity and on the psychometric properties of the PTPSQ-I(15) in different hospital settings or with other pathological conditions.

[Occupational safety and health risks in dock work: a narrative literature review. ]. / I rischi per la salute e la sicurezza nel lavoro portuale: revisione narrativa della letteratura.

BACKGROUND: Seaports are complex systems where workers can be exposed to a large variety of safety and health risks. Nevertheless, the literature available on this topic is scarce, if we exclude the specific area of the shipbuilding industry. OBJECTIVES AND METHODS: The aim of this paper is to provide a review of the scientific evidence concerning the occupational risks in seaports. Literature on this theme, obtained consulting the main databases (PubMed, Scholar and CCOHS) up to 2012, was reviewed. RESULTS: Loading/unloading procedures, transport and storage of goods in docks are identified as the major causes of injuries (such as falls, crushing and entrapments) and accidents (release of chemicals, fires or explosions). Moreover, attention is drawn to the risks related to goods handled: in particular, authors described risks of asphyxia or intoxication in restricted and poorly ventilated areas such as containers or ship holds. CONCLUSIONS: The following main prevention measures were identified by all authors as those most effective: implementation of workers' training and information and intensification of controls on ships, particularly concerning loading/unloading procedures and documents accompanying the goods.

Risk of mesothelioma following external beam radiotherapy for prostate cancer: a cohort analysis of SEER database.

PURPOSE: To investigate the association between external beam radiotherapy (EBRT) for prostate cancer and mesothelioma using data from the US Surveillance, Epidemiology, and End Results (SEER) cancer registries. METHODS: We analyzed data from the SEER database (1973-2009). We compared EBRT versus no radiotherapy. Incidence rate ratios (IRR) and 95 % confidence intervals (95 % CI) of mesothelioma among prostate cancer patients were estimated with multilevel Poisson models adjusted by race, age, and calendar year. Confounding by asbestos was investigated using relative risk of mesothelioma in each case's county of residence as a proxy for asbestos exposure. RESULTS: Four hundred and seventy-one mesothelioma cases (93.6 % pleural) occurred in 3,985,991 person-years. The IRR of mesothelioma was increased for subjects exposed to EBRT (1.28; 95 % CI 1.05, 1.55) compared to non-irradiated patients, and a population attributable fraction of 0.49 % (95 % CI 0.11, 0.81) was estimated. The IRR increased with latency period: 0-4 years, IRR 1.08 (95 % CI 0.81, 1.44); 5-9 years, IRR 1.31 (95 % CI 0.93, 1.85); ≥10 years, IRR 1.59 (95 % CI 1.05, 2.42). Despite the fairly strong evidence of association with EBRT, the population attributable rate of mesothelioma was modest-3.3 cases per 100,000 person-years. The cumulative incidence of mesothelioma attributable to EBRT was 4.0/100,000 over 5 years, 24.5/100,000 over 10 years, and 65.0/100,000 over 15 years. CONCLUSIONS: Our study provides evidence that EBRT for prostate cancer is a small but detectable risk factor for mesothelioma. Patients should be advised of risk of radiation-induced second malignancies.

Asbestos: a hidden player behind the cholangiocarcinoma increase? Findings from a case-control analysis.

PURPOSES: We conducted a case-control analysis to explore the association between occupational exposure to asbestos and cholangiocarcinoma (CC). METHODS: The study was based on historical data from 155 consecutive patients with CC [69 intrahepatic CC (ICC) and 86 extrahepatic CC (ECC)] referred to Sant'Orsola-Malpighi University Hospital between 2006 and 2010. The cases were individually matched by calendar period of birth, sex, and region of residence to historical hospital and population controls. Occupational exposure to asbestos was retrospectively assessed considering job titles obtained from work histories. Separate conditional logistic regression models were applied for ECC and ICC. Estimates were adjusted for smoking status and socioeconomic class. RESULTS: We matched 149 controls (median birth year: 1947; males: 56 %) to 41 cases of ICC (median birth year: 1946; males: 56 %) and 212 controls (median birth year: 1945; males: 48 %) to 59 cases of ECC (median birth year: 1945; males 51 %); 53 cases were not matched due to residence or birth year. We found an increased risk of ICC in workers exposed to asbestos (adjusted OR 4.81, 95 % CI 1.73-13.33); we also observed suggestive evidence that asbestos exposure might be associated with ECC (adjusted OR 2.09, 95 % CI 0.83-5.27). Sensitivity analysis restricted to patients from the Province of Bologna produced confirmatory figures. CONCLUSIONS: Our findings suggest that ICC could be associated with asbestos exposure; a chronic inflammatory pathway is hypothesized. Exposure to asbestos could be one of the determinants of the progressive rise in the incidence of ICC during the last 30 years.

Carcinoma of the pharynx and tonsils in an occupational cohort of asphalt workers.

BACKGROUND: We investigated a possible association between pharyngeal/tonsillar carcinoma and mixed carcinogen exposures in an asphalt roll company in Italy that used asbestos until 1979, when a new factory was built using a different production process. METHODS: We evaluated all workers involved in the entire production history of the company, divided into two subcohorts based on exposure status (workers in the original factory, 1964-1979, and those who worked only in the new factory, 1980-1997). We ascertained the vital status of the study population in February 2001. RESULTS: Among the subset of workers in the earlier subcohort, there were five deaths from pharyngeal/tonsillar carcinoma for a standardized mortality ratio of 21 (95% confidence interval = 8.8-51). No cases were recorded among workers hired after 1979. CONCLUSION: The increased standardized mortality ratio for this relatively rare cancer among workers exposed before 1979 may have been due to carcinogenic exposures at the plant.

Getting vaccinated or not getting vaccinated? Different reasons for getting vaccinated against seasonal or pandemic influenza.

BACKGROUND: A large number of studies have investigated the motivation behind health care workers (HCWs) taking the influenza vaccine. But with the appearance of pandemic influenza, it became important to better analyse the reasons why workers get vaccinated against seasonal and/or pandemic influenza. METHODS: Three main categories of reasons were identified with an Exploratory Factor Analysis. An analysis of variance (ANOVA) was used to verify the existence of differences between three categories of choices (taking of seasonal and pandemic vaccine, only the seasonal vaccine or none). In addition, a multinomial logistic regression analysis was performed to analyse the association between stated intentions and update of seasonal and pandemic vaccine. Questionnaires were returned from 168 HCWs (67.3% women). RESULTS: The results showed that age and being well-informed about vaccination topics are the most important variables in determining the choice to take the vaccine. CONCLUSIONS: The results highlight the importance of enhancing education programs to improve awareness among HCWs concerning the benefits of taking the influenza vaccination, with particular attention paid to younger workers.