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Biomedical subjects

T Bellander

Publications and source records attributed to T Bellander.

At least 19 recordsLinked to original sources
PubMed2006

Comparison of parental reports of smoking and residential air nicotine concentrations in children.

BACKGROUND: Using questionnaires to assess children's residential exposure to environmental tobacco smoke (ETS) may result in misclassification from recall and response bias. Questionnaire data have frequently been validated against urinary cotinine measurements, but rarely against actual measurements of residential air nicotine. OBJECTIVE: To compare questionnaire reported smoking with air nicotine concentrations in a large population of children and with urinary cotinine levels in a subpopulation; and to assess the potential impact of the symptom status of the children on the agreement between different measures of exposure. METHODS: The authors assessed residential exposure to ETS in 347 German, 335 Dutch, and 354 Swedish preschool and schoolchildren by questionnaire and air nicotine measurements, and in a subset of 307 German children by urinary cotinine measurements. They then compared the different measures of ETS exposure. RESULTS: In all countries, air nicotine concentrations increased with increasing questionnaire reported smoking in a dose-response fashion. Specificity and negative predictive values of questionnaire reports for nicotine concentrations were excellent. Sensitivity and positive predictive values were moderate to good. Excluding occasional smokers, the overall percentage of homes misclassified was 6.9%, 6.7%, and 5.1% in Germany, the Netherlands, and Sweden, respectively. Similar results were found for the agreement of urinary cotinine concentrations with questionnaire reports and air nicotine levels. There was no indication of underreporting by parents of symptomatic children. CONCLUSION: Despite some misclassification, questionnaire reports are an inexpensive and valid estimate of residential ETS exposure among preschool and school children.

Adult↗
PubMed2005

Exposure to traffic related air pollutants: self reported traffic intensity versus GIS modelled exposure.

BACKGROUND: In epidemiological studies of the potential health effects of traffic related air pollution, self reported traffic intensity is a commonly used, but rarely validated, exposure variable. METHODS: As part of a study on the impact of Traffic Related Air Pollution on Childhood Asthma (TRAPCA), data from 2633 and 673 infants from the Dutch and the German-Munich cohorts, respectively, were available. Parents subjectively assessed traffic intensity at the home address. Objective exposures were estimated by a combination of spatial air pollution measurements and geographic information system (GIS) based modelling using an identical method for both cohorts. RESULTS: The agreement rates between self reported and GIS modelled exposure--accumulated over the three strata of self assessed traffic intensity--were 55-58% for PM(2.5), filter absorbance (PM(2.5) abs), and nitrogen dioxide in Munich and 39-40% in the Netherlands. Of the self reported low traffic exposed group, 71-73% in Munich and 45-47% in the Netherlands had low modelled exposure to these three air pollutants. Of the self assessed high exposed subgroups in Munich (15% of the total population) and the Netherlands (22% of the total population), only 22-33% and 30-32% respectively had high modelled exposure to the three air pollutants. The subjective assessments tend to overestimate the modelled estimates for PM(2.5) and NO2 in both study areas. When analysis was restricted to the portion of the Dutch cohort living in non-urban areas, the agreement rates were even lower. CONCLUSIONS: Self reported and modelled assessment of exposure to air pollutants are only weakly associated.

Adult↗
PubMed2002

Traffic-related air pollution and respiratory health during the first 2 yrs of life.

As part of an international collaborative study on the impact of Traffic-Related Air Pollution on Childhood Asthma (TRAPCA), the health effects associated with long-term exposure to particles with a 50% cut-off aerodynamic diameter of 2.5 microm (PM2.5), PM2.5 absorbance, and nitrogen dioxide (NO2) were analysed. The German part of the TRAPCA study used data from subpopulations of two ongoing birth cohort studies (German Infant Nutrition Intervention Programme (GINI) and Influences of Lifestyle Related Factors on the Human Immune System and Development of Allergies in Children (LISA)) based in the city of Munich. Geographic information systems (GIS)-based exposure modelling was used to estimate traffic-related air pollutants at the birth addresses of 1,756 infants. Logistic regression was used to analyse possible health effects and potential confounding factors were adjusted for. The ranges in estimated exposures to PM2.5, PM2.5 absorbance, and NO2 were 11.9-21.9 microg m(-3), 1.38-4.39 x 10(-5) m(-1), and 19.5-66.9 microg x m3, respectively. Significant associations between these pollutants and cough without infection (odds ratio (OR) (95% confidence interval (CI)): 1.34 (1.11-1.61), 1.32 (1.10-1.59), and 1.40 (1.12-1.75), respectively) and dry cough at night (OR (95% CI): 1.31 (1.07-1.60), 1.27 (1.04-1.55), and 1.36 (1.07-1.74), respectively) in the first year of life were found. In the second year of life, these effects were attenuated. There was some indication of an association between traffic-related air pollution and symptoms of cough. Due to the very young age of the infants, it was too early to draw definitive conclusions from this for the development of asthma.

Air Pollution↗
PubMed2001

Exposure to chemical agents in Swedish aluminum foundries and aluminum remelting plants--a comprehensive survey.

Secondary aluminum melting is mainly performed in sand, die, and static die-casting foundries and remelting plants. In seven Swedish foundries and two remelting plants, the exposure and area concentrations of total dust, metals, organic gases, and vapors were determined mainly as daily, time-weighted averages (TWAs). For most combinations of jobs and agents, the exposure levels were well below the current threshold limits suggested by the American Conference of Governmental Industrial Hygienists (ACGIH). However, high exposure levels of mineral oil mist (geometric mean [GM] = 0.6 mg/m3) were observed in the die-casting process, with a maximum of 4 mg/m3. The findings were similar for total dust (GM = 5.1 mg/m3) and crystalline quartz (GM = 0.05 mg/m3) during molding operations in the sand foundries, maximum air concentrations being 31 mg/m3 and 0.22 mg/m3, respectively. Other agents which occasionally reached high exposure levels included furfuryl alcohol (up to 23 mg/m3 during furan binder use in sand foundries), aniline (up to 2.6 mg/m3 during thermal degradation of cold-box binders), and dimethylethylamine (up to 9 mg/m3) in the cold-box process used in static die-casting and sand foundries. The average aluminum exposure levels (GM = 0.043 mg/m3) were low in all foundries, individual values not exceeding 0.94 mg/m3. The exposures to metals were below 10 percent of their threshold limits. Similarly low levels were detected of polyaromatic hydrocarbons, phenol, formaldehyde, methylenebisphenyl diisocyanate, and phenylisocyanate. In the aluminum remelting plants, a few high exposure levels of total dust (GM = 1.4 mg/m3) up to 8 mg/m3 were detected in furnace workers. Aluminum and other metals were well below 10 percent of their threshold limits, with the exception of a few high concentrations of manganese, up to 0.14 mg/m3. The between-worker variability (GSDB) in the foundries for total dust, aluminum, and oil mist were on the order of 3-4. The heterogenicity of secondary aluminum melting requires assessment of a wide variety of chemical agents. For certain exposures, technical and medical monitoring programs are still needed.

Aluminum↗
PubMed2001

Using geographic information systems to assess individual historical exposure to air pollution from traffic and house heating in Stockholm.

A specific aim of a population-based case-control study of lung cancer in Stockholm, Sweden, was to use emission data, dispersion models, and geographic information systems (GIS) to assess historical exposure to several components of ambient air pollution. Data collected for 1,042 lung cancer cases and 2,364 population controls included information on residence from 1955 to the end of follow-up for each individual, 1990-1995. We assessed ambient air concentrations of pollutants from road traffic and heating throughout the study area for three points in time (1960, 1970, and 1980) using reconstructed emission data for the index pollutants nitrogen oxides (NO(x)/NO(2)) and sulfur dioxide together with dispersion modeling. NO(2) estimates for 1980 compared well with actual measurements, but no independently measured (study-external) data were available for SO(2), precluding similar validation. Subsequently, we used linear intra- and extrapolation to obtain estimates for all other years 1955-1990. Eleven thousand individual addresses were transformed into geographic coordinates through automatic and manual procedures, with an estimated error of < 100 m for 90% of the addresses. Finally, we linked annual air pollution estimates to annual residence coordinates, yielding long-term residential exposure indices for each individual. There was a wide range of individual long-term average exposure, with an 11-fold interindividual difference in NO(2) and an 18-fold difference in SO(2). The 30-year average for all study subjects was 20 microg/m(3) NO(2) from traffic and 53 microg/m(3) SO(2) from heating. The results indicate that GIS can be useful for exposure assessment in environmental epidemiology studies, provided that detailed geographically related exposure data are available for relevant time periods.

Adult↗
PubMed2000

Urban air pollution and lung cancer in Stockholm.

We conducted a population-based case-control study among men 40-75 years of age encompassing all cases of lung cancer 1985-1990 among stable residents of Stockholm County 1950-1990. Questionnaires to subjects or next-of-kin (primarily wives or children) elicited information regarding smoking and other risk factors, including occupational and residential histories. A high response rate (>85%) resulted in 1,042 cases and 2,364 controls. We created retrospective emission databases for NOx/NO2 and SO2 as indicators of air pollution from road traffic and heating, respectively. We estimated local annual source-specific air pollution levels using validated dispersion models and we linked these levels to residential addresses using Geographical Information System (GIS) techniques. Average traffic-related NO2 exposure over 30 years was associated with a relative risk (RR) of 1.2 (95% confidence interval 0.8-1.6) for the top decile of exposure, adjusted for tobacco smoking, socioeconomic status, residential radon, and occupational exposures. The data suggested a considerable latency period; the RR for the top decile of average traffic-related NO2 exposure 20 years previously was 1.4 (1.0-2.0). Little association was observed for SO2. Occupational exposure to asbestos, diesel exhaust, and other combustion products also increased the risk of lung cancer. Our results indicate that urban air pollution increases lung cancer risk and that vehicle emissions may be particularly important.

Adult↗
PubMed1998

Historical exposure to inorganic mercury at the smelter works of Abbadia San Salvatore, Italy.

Metallic mercury production from cinnabar ore may result in high exposures to inorganic mercury, that are difficult to assess separately from the exposures originating from underground extraction, and previously have only been scantily described. We retrieved and analysed the air and biological mercury determinations on workers involved in the smelting process of the Abbadia San Salvatore mine (Monte Amiata, Italy). Native mercury was not present in the ore, and the exposure in the underground extraction was low. The smelter operated from 1897 to 1983. Blood and urine (24/h urine collections and concentration samples) had been sampled in 1968 to 1982, and analysed for mercury by atomic absorption spectrophotometry, and relate to all subjects. Exposure to mercury in air had been determined in a small set of personal samples in 1982. The data relate to all jobs in the smelter process, and all jobs entailed substantial exposure to mercury. The overall distribution of breathing zone air, blood and urinary levels is right-skewed and similar to the log-normal distribution (air, median 48 micrograms/m3, n = 49; blood, arithmetic mean AM 49 micrograms/L; geometric mean GM 26 micrograms/L, n = 192; urinary excretion, AM 140 micrograms/24 h, GM 78 micrograms/24 h, n = 839; and urinary concentration, AM 160 micrograms/L, GM 83 micrograms/L, n = 632). Air, blood and urinary values show a high ratio of the between- and within-job variance, indicating differences in exposure by job. Cinnabar pigment production, of which the exposure has not been characterised previously, was the job with the highest air (AM 160 micrograms/m3) and urinary levels (excretion AM 690 micrograms/24 h; concentration AM 1100 micrograms/L). Other jobs with high urinary levels were soot purification, laboratory work, and bottling. Cleaning of condensers showed the highest blood level (AM 280 micrograms/L). There is a downwards time trend in mercury concentration in blood and in urine. The corresponding trend is not seen for urinary excretion levels, the reason for this being unclear. Roasters, which is the most frequently monitored group, show however a decreasing trend in all sets of data (e.g. the mean of urinary excretion decreased from 300 micrograms/24 h in 1968/69 to 50 micrograms/24 h in 1980/81). The mercury exposure experienced by the smelters of Abbadia San Salvatore is in line with the few available data on workers from other mercury mines and smelters, and our data confirm the high exposure levels in this occupational group, in particular at cinnabar pigment production, soot purification, and condenser cleaning.

Aerosols↗
PubMed1998

Cancer occurrence among European mercury miners.

OBJECTIVES: To study the carcinogenicity of inorganic mercury in humans. METHODS: We studied the mortality from cancer among 6784 male and 265 female workers of four mercury mines and mills in Spain, Slovenia, Italy and the Ukraine. Workers were employed between the beginning of the century and 1990; the follow-up period lasted from the 1950s to the 1990s. We compared the mortality of the workers with national reference rates. RESULTS: Among men, there was no overall excess cancer mortality; an increase was observed in mortality from lung cancer (standardized mortality ratio [SMR] 1.19, 95 percent confidence interval [CI] 1.03-1.38) and liver cancer (SMR 1.64, CI 1.18-2.22). The increase in lung cancer risk was restricted to workers from Slovenia and the Ukraine: no relationship was found with duration of employment or estimated mercu ry exposure. The increase in liver cancer risk was present both among miners and millers and was stronger in workers from Italy and Slovenia: there was a trend with estimated cumulative exposure but not with duration of employment, and the excess was not present in a parallel analysis of cancer incidence among workers from Slovenia. No increase was observed for other types of cancer, including brain and kidney tumours. Among female workers (Ukraine only), three deaths occurred from ovarian cancer, likely representing an excess. CONCLUSIONS: Exposure to inorganic mercury in mines and mills does not seem strongly associated with cancer risk, with the possible exception of liver cancer; the increase in lung cancer may be explained by co-exposure to crystalline silica and radon.

Carcinogens↗
PubMed1998

Mortality and cancer incidence in Swedish battery workers exposed to cadmium and nickel.

OBJECTIVE: To follow up cancer incidence and mortality in a group of Swedish battery workers exposed to nickel hydroxide and cadmium oxide. METHODS: 869 workers, employed at least one year between the years 1940 and 1980 were followed up until 1992. Vital status and causes of death were obtained from the Swedish cause of death registry. Cancer morbidity was retrieved from the Swedish cancer registry. Regional reference rates were used to compute the expected numbers of deaths and cancers. RESULTS: Up to 31 December, 1992, a total of 315 deaths (292 in men and 23 in women) had occurred in the cohort. For men, the overall standardised mortality ratio (SMR) was 106 (95% confidence interval (95% CI) 93.7 to 118) and for women 83.8 (95% CI 53.1 to 126). The SMRs for total cancer mortality were 125 (95% CI 98.2 to 157) for men and 69.5 (95% CI 25.5 to 151) for women. The SMR for lung cancer in men was 176 (95% CI 101 to 287). No lung cancers were found among female workers. Up to 31 December, 1991, a total of 118 cancers had occurred in the cohort. A significantly increased standardised incidence ratio (SIR) was found for cancer of the nose and nasal sinuses in men, three cases v 0.36 expected, yielding an SIR of 832 (95% CI 172 to 2430). Applying a 10 year latency period in cohort members exposed to > or = 1000 micrograms cadmium/m3, the SIR was 1107 (95% CI 134 to 4000). Similarly, for cohort members exposed to 2000 micrograms nickel/m3, the SIR was 1080 (95% CI 131 to 3900). CONCLUSION: There was an increased overall risk for lung cancer, but no exposure-response relation between cumulative exposure to cadmium or nickel and risk of lung cancer. There was a highly significant increased risk of cancer of the nose and nasal sinuses, which may be caused by exposure to nickel or cadmium or a combination of both exposures.

Adult↗
PubMed1997

In vivo analysis of cadmium in battery workers versus measurements of blood, urine, and workplace air.

OBJECTIVES: To measure in vivo the cadmium concentrations in kidney cortex (kidney-Cd) and in superficial liver tissue (liver-Cd) of nickel cadmium battery workers, and to compare the results with other commonly used estimates of cadmium exposure (current concentrations of cadmium in blood (B-Cd) and urine (U-Cd)) or repeated measurements of cadmium in workplace air (CumAir-Cd). METHODS: The study comprised 30 workers with a range of duration of exposure of 11-51 years. 13 subjects were currently employed, whereas the other 17 had a median period without occupational exposure of eight years before the measurements. The in vivo measurements were made with an x ray fluorescence technique permitting average detection limits of 30 and 3 micrograms cadmium per g tissue in kidney and liver, respectively. RESULTS: 19 of 30 (63%) people had kidney-Cd and 13 of 27 (48%) had liver-Cd above the detection limits. Kidney-Cd ranged from non-detectable to 350 micrograms/g and liver-Cd from non-detectable to 80 micrograms/g. The median kidney-Cd and liver-Cd were 55 micrograms/g and 3 micrograms/g, respectively. Kidney-Cd correlated significantly with B-Cd (r, 0.49) and U-Cd (r, 0.70), whereas liver-Cd correlated significantly with U-Cd (r, 0.58). Neither kidney-Cd nor liver-Cd correlated with the CumAir-Cd. The prevalence of beta 2-microglobulinurea increased with increased liver-Cd. CONCLUSIONS: Current U-Cd can be used to predict the kidney-Cd and liver-Cd measured in vivo. In vivo measurements of kidney-Cd and liver-Cd were not shown to correlate with the individual cadmium exposure estimates, obtained by integration of the cadmium concentration in workplace air. There may be several reasons for this, including uncertainties in the estimate of the individual cumulative exposures as well as in the in vivo measurements. There was a suggestion of a relation between liver-Cd and tubular proteinuria.

Aged↗
PubMed1996

Exposure to styrene and mortality from nervous system diseases and mental disorders.

Chronic low-dose exposure to solvents has been associated in epidemiologic studies with chronic neurotoxicity, but the evidence is not consistent. Styrene causes acute disturbances in the central and peripheral nervous systems. To determine if exposure to styrene may contribute to chronic diseases of the central nervous system, the authors examined mortality from nervous system diseases, mental disorders, and suicide in relation to styrene exposure in an international historical cohort study. The cohort involved 35,443 workers employed during 1945-1991 in the reinforced plastics industry, where high exposures to styrene occur. Indicators of exposure were reconstructed through job histories and environmental and biologic monitoring data. Poisson regression was used for internal comparisons. Mortality from diseases of the central nervous system (27 deaths) increased with time since first exposure, duration of exposure, average level of exposure, and cumulative exposure to styrene. A quadratic model described best the dose-response shape for cumulative exposure and duration of exposure with the highest risks at around 300 ppm-years and 5 years, respectively, and a subsequent decrease in risk in the highest exposure categories. Mortality from epilepsy increased monotonically with all styrene exposure indicators, while associations for degenerative diseases of the central nervous system were generally weaker. Mortality from mental disorders and suicide decreased with increasing duration of exposure and cumulative exposure, while there was no trend with time since first exposure and average exposure to styrene. These findings suggest that, in addition to the known acute effects, exposure to styrene may contribute to chronic diseases of the central nervous system.

Cause of Death↗
PubMed1996

Exposure to styrene and mortality from nonmalignant respiratory diseases.

A cohort of 34,560 men and 6128 women employed in 660 European factories manufacturing reinforced plastic products, followed up originally to assess the risk of cancer, was used to assess the risk of non-malignant respiratory diseases associated with exposure to styrene. Mortality from pneumonia was associated with intensity of exposure to styrene, but this may have been due to chance. Mortality from bronchitis, emphysema, and asthma was not associated with styrene exposure.

Cohort Studies↗
PubMed1996

Exposure to styrene and mortality from nonmalignant diseases of the genitourinary system.

OBJECTIVES: A historical cohort study was carried out to investigate mortality from nonmalignant diseases of the genitourinary system among workers in the reinforced plastics industry, where high workroom concentrations of styrene are encountered. METHODS: The external comparisons in this report were based on an average of 12.6 years of retrospective follow-up of 35 443 workers who were first employed in the reinforced plastics industry during 1945-1991 and were known to have been exposed to styrene in their work. For the internal comparisons, 2641 subjects with incomplete occupational histories were excluded, leaving 32 802 subjects. Previous individual exposure histories to styrene were reconstructed through job histories and environmental and biological monitoring data. RESULTS: Mortality from nonmalignant diseases of the genitourinary system (N = 20) was associated with average exposure to styrene (P for trend 0.05). Weaker increasing trends in risk were seen for time since first exposure and cumulative exposure, while no increase was identified for duration of exposure. There was a significant increasing trend in mortality from nephritis and nephrosis (N = 5), associated with an increasing average level of exposure to styrene (P for trend 0.03). No clear trend was observed for time since first exposure, duration of exposure, or cumulative exposure. CONCLUSIONS: In this large cohort study of workers exposed to styrene, mortality from nonmalignant diseases of the genitourinary system increased as the average intensity of exposure increased. This finding indicates that other data should be scrutinized.

Air Pollutants, Occupational↗
PubMed1995

Surveillance of mortality and cancer incidence among Swedish graphite electrode workers.

Mortality and cancer incidence were investigated among 901 workers at a Swedish company manufacturing graphite electrodes. Current and previous measurements of personal exposure to benzo[a]pyrene were used to calculate individual exposure estimates. Smoking habits were investigated by questionnaire. There were 42 deaths during the study period (1968-1989), whereas 32.3 would be expected, based on age, sex, time, and county-specific population statistics. Three cancers of the respiratory system were found vs 1.2 expected. The overall mortality was slightly elevated, mainly due to an increased number of deaths from external causes. Thus far, no excess risk of cancer has been documented in this cohort. The results indicate that an increased risk of respiratory cancer may be present, but influence from chance cannot be ruled out due to small numbers. The cohort will be under continued surveillance.

Benzo(a)pyrene↗
PubMed1994

Cancer mortality in a historical cohort study of workers exposed to styrene.

OBJECTIVES: The goal of this study was to determine whether exposure to styrene is associated with an increased risk for neoplasms of the lymphatic and hematopoietic tissues. METHODS: A historical cohort study was conducted in Denmark, Finland, Italy, Norway, Sweden, and the United Kingdom. It involved 40,688 workers ever employed in the reinforced plastics industry, where high exposure to styrene occurs. Exposure to styrene was reconstructed through job histories and environmental and biological monitoring data. Cause-specific national death rates were used as the reference. Poisson regression was applied for internal comparisons. RESULTS: Among the exposed workers, no excess was observed for mortality from all neoplasms. Mortality from neoplasms of the lymphatic and hematopoietic tissues increased with time since first exposure and average level of exposure to styrene, but was not consistently associated with duration of exposure or with cumulative exposure. CONCLUSIONS: These findings leave open the possibility of an excess risk of neoplasms of the lymphatic and hematopoietic tissues among workers exposed to styrene.

Cohort Studies↗