Biomedical subjects

L Barregård

Publications and source records attributed to L Barregård.

At least 19 recordsLinked to original sources

PubMed2002

Influence of solvent exposure and aging on cognitive functioning: an 18 year follow up of formerly exposed floor layers and their controls.

OBJECTIVES: To extend our knowledge of how exposure to neurotoxic substances during working life affects cognitive functioning in the long term. Does long term occupational exposure to organic solvents lead to aggravated cognitive impairment later in life? METHODS: A follow up was conducted of floor layers exposed to solvents and their unexposed referents (carpenters) 18 years after the baseline assessment. The pattern of cognitive changes in the two groups was compared, with the same 10 neuropsychological tests from the test battery for investigating functional disorders (TUFF) that were used at baseline. The study included 41 floor layers and 40 carpenters. A medical examination focused on health at the present and during the past 18 years. An extensive exposure assessment made in the initial study included questionnaires, interviews, and measurements. Additional exposure during the follow up period was minor, as explored in interviews at follow up. RESULTS: The entire group of floor layers did not deteriorate significantly more over time than did the carpenters. However, among the oldest subjects (>60 years), only floor layers showed decline in visual memory. Moreover, the most highly exposed floor layers deteriorated significantly more than their referents in visual memory and perceptual speed, and they tended to display larger decrements in motor speed. Significant dose effect relations were found; higher cumulative exposure was associated with decrements in visual episodic memory, perceptual speed and attention, and visuospatial skill. CONCLUSIONS: The hypothesis that floor layers would deteriorate more in cognitive performance than their unexposed referents over a period of 18 years was partly supported by the results of this study. The results are consistent with the view that the negative effects of exposure to solvents may interact with the normal aging process, primarily at heavy exposure.

Adhesives↗

PubMed2001

Validity of self-reports of hand eczema.

The validity of questionnaire answers with respect to hand eczema was investigated. Car mechanics, dentists and office workers answered a questionnaire on the occurrence of hand eczema on any occasion during the past 12 months. "Yes"-responders and a random sample of "no"-responders were subsequently interviewed and examined by a dermatologist. 10.0% of the car mechanics, 12.0% of the dentists and 12.5% of the office workers were found to have hand eczema despite previous "no"-answers. In the same populations, 81%, 94% and 80% of the "yes"-answers were confirmed at the clinical examination. Considering false-negative and false-positive answers, the sensitivity was 53-59% and the specificity 96-99% in the 3 groups. The 1-year prevalence changed from self-reported 15% to estimated 21% in the car mechanics, from 15% to 24% in the dentists and from 15% to 23% in the office workers. It is concluded that self-reported 1-year prevalence of hand eczema considerably underestimates the true prevalence.

Adult↗

PubMed2001

Etiologic factors influencing the prevalence of demarcated opacities in permanent first molars in a group of Swedish children.

The aim of this study was to determine possible etiological factors for a developmental enamel defect, i.e. demarcated opacities, affecting the permanent first molars. A questionnaire about possible etiological factors of enamel developmental defects was filled in by the parents of 8-yr-old children (n=516) prior to a dental examination of permanent teeth. Demarcated opacities of permanent first molars had been found in 18.4% of the children in a previous study of these children. Fifteen % had more than one tooth affected indicating systemic causation. Questions were asked about mother's health and medication during pregnancy, birth complications, health and medication of the child during the first 3 yr of life, breast-feeding, heredity, and fluoride supplements. The affected children, especially the boys, were reported to have had more health problems, in particular asthma (but only 4 cases), during the first year of life. Use of antibiotics was also more common among the affected children, but owing to a strong co-variance with health problems these factors could not be separated. Breast-feeding history was similar in children with and without enamel defects. The etiology of hypomineralized first molars is not yet fully understood, but based on the results of this retrospective study, health problems in infancy, especially respiratory diseases, seem to be involved.

Age Factors↗

PubMed2001

Protective gloves in Swedish dentistry: use and side-effects.

BACKGROUND: During the 1980s routine wearing of gloves in dentistry was recommended by health authorities in several countries. However, prolonged glove use is associated with side-effects of irritant and allergic origin. OBJECTIVES: To investigate the extent of glove use and self-reported glove intolerance reactions among Swedish dentists, and to examine how far IgE-mediated allergy to natural rubber latex (NRL) occurs in subjects who report rapid itching when in contact with protective gloves. SUBJECTS/METHODS: A postal questionnaire was answered by 3083 of 3500 licensed dentists, a response rate of 88%. Of the dentists who reported rapidly occurring itching of the hands from gloves, 131 of 170 attended a clinical examination including a skin prick test (SPT) and a serological examination (RAST) for IgE-mediated allergy. RESULTS: Seventy-three per cent of the dentists reported daily glove use of more than 2 h, 48% more than 6 h a day, and 6% reported no use. NRL gloves were used most frequently (P < 0.001) and were the main material that elicited symptoms (P < 0.001). Female dentists reported more frequent glove use than males, as did young dentists (P < 0.001) compared with older ones. Females also preferred vinyl gloves. Glove intolerance reactions were reported by 723 (23%) dentists, [females 28%, males 21% (P < 0.001)] and were more common in younger dentists. Of the 417 dentists with reported hand eczema during the previous year, 54% reported glove intolerance, compared with 20% of the dentists without hand eczema (P < 0.001). A logistic regression analysis including hand eczema, age, sex and atopy showed that all these factors contributed significantly to the risk of glove intolerance, and that hand eczema was a stronger factor than atopy. In 15 of 131 (11%) dentists examined for reported glove-related itch, latex allergy was verified by SPT and/or RAST. Glove-related conjunctivitis, rhinitis and asthma, in contrast to skin symptoms, showed a significant association with IgE-mediated allergy to NRL. CONCLUSIONS: Swedish dentists show good compliance with the recommendations for routine glove use. Intolerance reactions are frequently reported, especially by dentists with hand eczema, which emphasizes the need for preventive skin care programmes. Glove-related symptoms from mucous membranes showed a higher association with IgE-mediated allergy to NRL than reported itching of the skin, a fact that should be considered when composing screening questionnaires for NRL sensitization

Adult↗

PubMed2001

The prevalence of demarcated opacities in permanent first molars in a group of Swedish children.

The permanent teeth of 516 7- and 8-year-old Swedish children from a low-fluoride area were examined for developmental enamel defects. Special attention was paid to demarcated opacities in permanent first molars and permanent incisors (MIH). The examination was done in their schools, using a portable light, a mirror, and a probe. The modified DDE index of 1992 was used for recording the enamel defects, supplemented with a further classification into severe, moderate, and mild defects. Demarcated opacities in permanent first molars were present in 18.4% of the children. The mean number of hypomineralized teeth of the affected children was 3.2 (standard deviation, 1.8), of which 2.4 were first molars. Of the children 6.5% had severe defects, 5% had moderate defects, whereas 7% had only mildly hypomineralized teeth. In conclusion, hypomineralized first molars appeared to be common and require considerable treatment in the Swedish child population.

Child↗

PubMed2001

Work-related skin and airway symptoms among Swedish dentists rarely cause sick leave or change of professional career.

Dentistry usually is 'wet work' with risk of damage to the skin barrier, and the hands may be exposed to skin irritants and contact-sensitizing substances used in dental materials or gloves. Airway irritants may also be present. This study assessed the consequences of work-related skin and airway symptoms among dentists in terms of contact with health authorities, sick leave, or changes in the professional career. A questionnaire on these factors was answered by more than 3000 Swedish dentists. Only 6% of the respondents had consulted a physician, although 22% had noted work-related skin symptoms. In 2% the skin symptoms had caused sick leave, and about 2% had reported their skin symptoms as an occupational disease. Two per cent had consulted a physician owing to work-related airway symptoms, which is a minor part of the 13% who had experienced such symptoms when in contact with dental materials. Twenty-five dentists (<1%) had been on sick leave because of work-related airway symptoms. Only 1 dentists reported change of activities or occupation owing to work-related skin or airway symptoms, and in most cases these symptoms only contributed to their decision. In summary, whereas sick leave in dentists because of musculoskeletal problems may be common, the present study shows that this is not the case for work-related skin or airway symptoms, and such symptoms seldom affect the dentists' professional career.

Adult↗

PubMed2001

Heterogeneity in sources of exposure variability among groups of workers exposed to inorganic mercury.

Many exposure assessment strategies rely on the occupational group as the unit of analysis in which workers are classified on the basis of job title, location, or on other characteristics related to the workplace or the job. Although statistical methods that combine exposure data collected on workers from different occupational groups are more efficient, the underlying assumption that the degree of variation over time and among workers is the same for all groups has yet to be fully investigated. Given the utility of different modeling approaches when assessing exposures, we investigated assumptions of homogeneity of variance within and between workers using both random- and mixed-effects models. In our study of four groups of workers exposed to inorganic mercury (Hg) at a chloralkali plant, there was no evidence of significant heterogeneity in the levels of variation over time or between workers for air Hg levels. For the biological monitoring data, however, our findings indicate that groups did not share common levels of variability and that it was not appropriate to pool the data and obtain single estimates of the within- and between-worker variance components. Classification of job group as a random or fixed effect had no effect on the results and yielded the same conclusions when the models were compared. To illustrate effects related to the proper specification of a model, the likelihood of exceeding certain levels (which is a function of the parameters of the underlying distribution of the natural log-transformed exposures) was evaluated using the results obtained from the different models. Although the probability that workers' mean exposures exceeded occupational exposure limits for air, urine and blood Hg was generally low (<10%) for all groups except maintenance workers, the estimated values sometimes varied depending upon the particular model that was applied. Given the growing use of random- and mixed-effects models that combine data across occupational groups, additional studies are warranted to evaluate whether it is reasonable to assume common variances and covariances among measurements collected on workers from different groups.

Analysis of Variance↗

PubMed2000

Contact allergy and hand eczema in Swedish dentists.

Hand eczema and contact allergy in Swedish dentists were studied in a multidisciplinary project. The aims of the study were to establish diagnoses, to investigate the occurrence of contact allergy, in particular to (meth)acrylates, and to evaluate certain consequences of hand eczema. A postal questionnaire on skin symptoms, atopy and occupational experience was mailed to 3,500 dentists aged <65 years, and licensed 1965-1995. The response rate was 88%. Among dentists living in 3 major cities, 14.9% (n= 191) reported hand eczema during the previous year. They were invited to a clinical examination, including patch testing with a standard and a dental series. 158/191 (83%) dentists attended, and hand eczema diagnosis was confirmed in 149/158 (94%). Irritant contact dermatitis was diagnosed in 67% and allergic contact dermatitis in 28%. On patch testing, 50% presented at least 1 positive reaction. The most frequent allergens were nickel sulfate, fragrance mix, gold sodium thiosulfate and thiuram mix. 7 (5%) had positive reactions to (meth)acrylates, all to 2-hydroxyethyl methacrylate and 6 also to ethyleneglycol dimethacrylate. 38% had consulted a physician, 4% had been on sick-leave and 1% had changed occupational tasks due to hand eczema. No dentist with allergy to acrylates had been on sick-leave or changed occupation. It is concluded that dentistry is a high-risk occupation for hand eczema, and that irritant contact dermatitis is most common. The prevalence of contact allergy to acrylates was below 1% in the population of responding dentists, and in most cases did not have serious medical, social or occupational consequences.

Adult↗

PubMed2000

Variability in airborne and biological measures of exposure to mercury in the chloralkali industry: implications for epidemiologic studies.

Exposure assessment is a critical component of epidemiologic studies, and more sophisticated approaches require that variation in exposure be considered. We examined the intra- and interindividual sources of variation in exposure to mercury vapor as measured in air, blood, and urine among four groups of workers during 1990-1997 at a Swedish chloralkali plant. Consistent with the underlying kinetics of mercury in the body, the variability of biological measures was dampened considerably relative to the variation in airborne levels. Owing to the effects of intraindividual variation, estimating workers' exposures from a few measurements can attenuate measures of effect. To examine such effects on studies relating long-term exposure to a continuous health outcome, we evaluated the utility of each exposure measure by comparing the necessary sample sizes required for accurate estimation of a slope coefficient obtained from a regression analysis. No single measure outperformed the others for all groups of workers. However, when workers were evaluated together, creatinine-corrected urinary mercury better discriminated workers' exposures than airborne or blood mercury levels. Thus, pilot studies should be conducted to examine variability in both air and biomonitoring data because quantitative information about the relative magnitude of the intra- and interindividual sources of variation feeds directly into our efforts to design an optimal sampling strategy when evaluating health risks associated with occupational or environmental contaminants.

Adult↗

PubMed1999

Tissue levels of mercury determined in a deceased worker after occupational exposure.

OBJECTIVES: To examine mercury (Hg) and selenium (Se) levels in autopsy samples from a thermometer worker who had been exposed over a long period to, and monitored for, mercury vapor. CASE REPORT: Hg and Se levels were determined using radiochemical neutron activation analysis in a worker who had commited suicide 4 weeks after the end of 14 years of exposure and in an unexposed age-matched referent. Histochemical staining of cerebellum was performed according to the method of Danscher and Schroder. RESULTS: The Hg concentrations (wet weight) were 25 microg/g in the kidney cortex, 1.2 microg/g in the liver, 0.72 microg/g in the lung, 0.025 microg/g in the testis, and 0.014-0.018 microg/g in the cerebellum (gray matter, dentate nucleus, and white matter). The Se level in the kidney cortex was high, 4.6 microg/g, whereas the concentration detected in the other tissue samples was normal. Light microscopy of the cerebellum was normal, and no histochemical staining for mercury was observed. Autopsy samples from the referent showed low Hg and Se levels consistent with other reports. CONCLUSIONS: The observed kidney-Hg, which was 50-100 times higher than that occurring in the general population, is in agreement with previous sparse data from ongoing occupational exposure. The high Se level detected in the kidney indicates coaccumulation with mercury. The low Hg concentration found in the cerebellum was unexpected, since some reports have shown much higher brain-Hg long after the cessation of exposure.

Adult↗

PubMed1999

Prevalence of self-reported hand eczema and skin symptoms associated with dental materials among Swedish dentists.

In the present study we investigated the prevalence of self-reported hand eczema as well as subjective associations between skin symptoms and composite/bonding or other dental materials among Swedish dentists. A questionnaire on skin symptoms, atopy, occupational experience, and other background factors was sent to a random sample (n=3,500) of all dentists licensed since 1965. This group corresponds to about half of the country's occupationally active dentists. The response rate was 88%. The questionnaire had previously been validated against clinical dermatological examination of subjects reporting hand eczema. The prevalence of dry and rough skin on the hands was high (45%). Hand eczema during the previous 12 months was reported by 13.5%. Dry skin and hand eczema were more common among dentists than in two age-matched general population samples investigated using identical questions. The difference versus the general population was most pronounced (about two-fold) among male dentists. A history of childhood eczema was the most important predictor for adult hand eczema, with a prevalence ratio of 2.4 compared to dentists without childhood eczema. Seven % reported skin symptoms when working with acrylic resins, and 15% had experienced rapid itching related to protective gloves.

Acrylic Resins↗

PubMed1999

Trail making test in chronic toxic encephalopathy: performance and discriminative potential.

The objective of this study was to examine the influence of chronic toxic encephalopathy (CTE) on Trail Making Test (TMT) performance, with special focus on the discriminative potential of this test. We assessed TMT performance in patients diagnosed with CTE, patients with similar symptoms but no diagnosis, and healthy participants. Inferior performance was seen in CTE, and increasing age had a negative effect on TMT performance only for the CTE group. This effect was most pronounced in TMT-B. However, the ability of the TMT to identify CTE was low, whereas all healthy participants were identified as healthy. Thus, the sensitivity of TMT alone was low, but it succeeded in correctly classifying normal subjects. The pattern of results indicates that normal TMT performance may be seen in individuals with mild to moderate brain syndromes, such as CTE, whereas poor performance should not be expected in healthy individuals.

Adult↗

PubMed1999

Cadmium, mercury, and lead in kidney cortex of the general Swedish population: a study of biopsies from living kidney donors.

Cadmium, mercury, and lead concentrations were determined in deep-frozen kidney cortex biopsies taken from 36 living, healthy Swedish kidney donors (18 males and 18 females), who were 30-71 (mean 53) years of age. Information about occupation, smoking, the presence of dental amalgam, and fish consumption could be obtained for 27 of the donors. The samples (median dry weight 0.74 mg) were analyzed using inductively coupled plasma mass spectrometry, and the results were transformed to wet-weight concentrations. The median kidney Cd was 17 micrograms/g (95% confidence interval, 14-23 micrograms/g), which was similar in males and females. In 10 active smokers, the median kidney Cd was 24 micrograms/g, and in 12 who never smoked, it was 17 micrograms/g. The median kidney Hg was 0.29 micrograms/g, with higher levels in females (median 0.54 micrograms/g) than in males (median 0.16 micrograms/g). Subjects with amalgam fillings had higher kidney Hg (median 0.47 micrograms/g, n = 20) than those without dental amalgam (median 0.15 micrograms;g/g, n = 6), but kidney Hg was below the detection limit in some samples. Nearly half of the samples had kidney Pb below the detection limit. The median kidney Pb was estimated as 0. 14 micrograms/g. This is the first study of heavy metals in kidney cortex of living, healthy subjects, and the results are relatively similar to those of a few previous autopsy studies, indicating that results from autopsy cases are not seriously biased in relation to kidney metal concentrations in the general population. Cd concentrations in those who never smoked were relatively high, indicating considerable Cd intake from the diet in Sweden. The effect of dental amalgam on kidney Hg was as expected, although the reason for the difference in Hg levels between males and females is unclear.

Adult↗

PubMed1998

[Mercury exposure from dental amalgam. Risk assessment and clinical evaluation].

Inorganic mercury is absorbed in small amounts from dental amalgam fillings. Exposure can be calculated by measuring the level of mercury in the blood or urine (u-Hg). The average u-Hg in Norwegians is approximately 2-3 micrograms/g creatinine (approximately 1-2 nmol/mmol creatinine). Classic signs of mercury poisoning occur in a fraction of long-term exposed subjects with u-Hg > 100 micrograms/g creatinine (56 nmol/mmol creatinine). Subtle effects (e.g. enzymuria, altered selenium metabolism, and changes in tremor spectra) have been reported in humans at average levels of 20-35 micrograms/g creatinine (approximately 11-20 nmol/mmol creatinine). There is widespread concern about possible adverse effects of mercury from amalgam fillings. Data on exposure-response relationships make it less likely that low-level mercury exposure from amalgam fillings should cause symptoms or physical signs. Studies of the association between symptoms and amalgam fillings have been negative. Patients with symptoms allegedly caused by mercury from amalgam should undergo thorough medical examination. Based on the patient's symptoms and physical signs adequate time should be allowed for careful recording of medical history, physical examination and relevant laboratory tests.

Dental Amalgam↗

PubMed1997

Blood lead in Uruguayan children and possible sources of exposure.

Blood samples and questionnaire background data were collected from 96 children (age 2-14 years) living in urban, suburban, or rural areas with varying traffic intensity and industrial lead pollution in Uruguay. Spot samples of tap water were collected from the homes of 44 children, and samples of top soil were taken from seven areas. Samples of air-borne dust were collected in central and suburban Montevideo. Blood lead concentrations (B-Pb) in children ranged between 47 and 191 (mean 96) micrograms/L and exceeded in 36% of the children 100 micrograms/L, the intervention level adopted by the United States Centers for Disease Control. Lead in tap water ranged from 0.2 to 230 (mean 15) micrograms/L and exceeded in 39% of the samples the maximum level recommended by WHO, 10 micrograms/L. Lead pipes were used in parts of the water supply systems. Lead in air varied between different locations from 0.15 to 1.7 micrograms/m3, highest in the very center of Montevideo. The median soil lead ranged from 6 to 2100 micrograms/g and was highest in industrially polluted areas. At multiple regression analysis, B-Pb was significantly associated only with age (P = 0.032) and traffic intensity at school (P = 0.045). No significant impact on B-Pb of lead in water or soil could be established.

Adolescent↗

PubMed1997

Polychlorinated dibenzo-p-dioxin and dibenzofuran levels and patterns in polyvinylchloride and chloralkali industry workers.

The production of chlorine and vinyl chloride (VCM) is associated with the formation of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs). The objective of the present study was to determine whether the levels and congener patterns of PCDDs and PCDFs in the blood of workers involved in the production of such substances could be related to their occupational environment. PCDD and PCDF levels in blood plasma from VCM and chloralkali workers and in referents were determined by means of high-resolution gas chromatography/high resolution mass spectrometry (HRGC/HRMS) techniques and the results were evaluated through principal component analysis (PCA). The overall levels of PCDDs and PCDFs were low, but the relative congener distribution detected in the workers differed from that found in the referents. 1,2,3,4,6,7,8-HpCDF, 1,2,3,4,7,8- and 1,2,3,6,7,8-HxCDFs are congeners related to work in VCM and chloralkali industries. Exposure to PCDDs and PCDFs in these industrial environments changes the congener-distribution pattern in the blood of workers as compared with referents. A combination of isomer-specific analysis of PCDDs and PCDFs in blood plasma and PCA is suitable for the differentiation between nonoccupational and occupational exposure and provides a means of assessing workers' exposure situation in different occupational settings.

Animals↗

PubMed1997

A study of autoantibodies and circulating immune complexes in mercury-exposed chloralkali workers.

UNLABELLED: Inorganic mercury may cause immunologically mediated disease: e.g., glomerulonephritis, acrodynia, and contact allergy. Animal models have demonstrated the importance of genetic factors in determining susceptibility and resistance to autoimmunity, as well as the specific manifestation of the autoimmune response. Findings in groups of workers with occupational exposure to inorganic mercury have been inconsistent. OBJECTIVE: To investigate whether an immune response, caused by exposure to inorganic mercury (Hg), could be shown in occupationally exposed workers. METHODS: Immunoglobulin G (IgG), antinuclear autoantibodies, antibodies against thyroid, stomach or kidney antigens using indirect immunofluorescence, antibodies against glomerular basement membrane using ELISA, and circulating immune complexes in serum, and albumin in urine, were examined in Hg-exposed workers and controls. The two groups, 41 male chloralkali workers exposed to Hg vapour (mean exposure time 9 years) and 41 unexposed controls were age-matched and recruited from the same company. Hg concentrations in whole blood (B-Hg), plasma (P-Hg), and urine (U-Hg) were determined using cold vapor atomic spectrometry. DESIGN: Cross-sectional study. RESULTS: The mean B-Hg, P-Hg and U-Hg levels were 46 nmol/l, 37 nmol/l, and 27 micrograms/g creatinine in the exposed group, and 17 nmol/l, 6.9 nmol/l, and 3.4 micrograms/g creatinine in the referents. No statistically significant differences were found regarding IgG levels, urinary albumin excretion, prevalence of abnormal titers of autoantibodies or circulating immune complexes. There were no statistically significant associations between autoantibodies or immune complexes on the one hand and mercury exposure indices on the other. CONCLUSION: The results indicate that, if and when lasting autoimmune response occurs at the mercury exposure levels of the present study, it is uncommon. A small fraction of humans may, however, be susceptible to the development of autoimmunity, and there is also a possible "healthy worker" selection. Thus cross-sectional studies of moderate numbers of active workers will have low power to demonstrate autoimmune effects.

Adolescent↗

PubMed1997

Urinary excretion of mercury, copper and zinc in subjects exposed to mercury vapour.

The excretion of mercury, copper and zinc in urine, and mercury in whole blood and plasma, was determined in 40 chloralkali workers exposed to mercury vapour and 40 age-matched referents. The Hg concentrations in whole blood, plasma and urine were higher in the exposed group (35 nmol l-1, 30 nmol l-1, and 11.5 nmol mmol-1 creatinine, respectively) in comparison with the reference group (15 nmol l-1, 6.3 nmol l-1, and 1.8 nmol mmol-1 creatinine, respectively). The urinary copper excretion was similar in the two groups, while U-Zn excretion was significantly higher (P = 0.04) in the exposed group, median 0.83 mumol mmol-1 creatinine versus 0.76 munmol mmol-1 creatinine in the reference group. In a subgroup of exposed workers with current U-Hg above 11.5 nmol l-1 mmol-1 creatinine (20 micrograms g-1 creatinine) the median U-Zn was 1.1 mumol mmol-1 creatinine. In both groups smokers had high U-Zn levels than non smokers. When both U-Hg and smoking were taken into account in a linear regression model, there was a significant association between U-Hg and U-Zn in the combined group of exposed and referents (P = 0.002). This study indicates that mercury exposure in humans, as in animals, causes increased urinary excretion of zinc. The mechanisms may be induced synthesis of metallothionein in the kidneys, displacement of Zn from preexisting metallothionein by Hg, or a decreased reabsorption of zinc in the kidneys owing to a slight tubular dysfunction.

Adolescent↗