PubMed Health⌕ Search

Biomedical subjects

A M Hansen

Publications and source records attributed to A M Hansen.

At least 37 records · Page 2Linked to original sources
PubMed1994

Correlation between work process-related exposure to polycyclic aromatic hydrocarbons and urinary levels of alpha-naphthol, beta-naphthylamine and 1-hydroxypyrene in iron foundry workers.

In two Danish iron foundries the concentration of polycyclic aromatic hydrocarbons (PAH) in 24 personal air samples of workers employed in selected processes, i.e. melters, melted iron transporters, casters, machine molders, hand molders, shake-out workers and finishing workers, were measured and correlated to levels of 1-hydroxypyrene, alpha-naphthol and beta-naphthylamine in the urine of exposed workers. The highest total airborne PAH concentrations (sum of 15 selected PAH compounds: 9.6-11.2 micrograms/m3) were associated with casting, machine molding, and shake-out. The highest concentrations of the sum of six selected airborne carcinogenic PAH compounds were found for melting, casting and machine and hand molding. As seen in other working environments involving low-level PAH exposure, the content of naphthalene was high, in general exceeding 85% of the total content of PAH compounds. The present study demonstrates that 1-hydroxypyrene is a useful and direct biomarker of low-dose occupational exposure to PAH compounds. Molding and casting had the highest pyrene levels in iron foundries. Furthermore, the data shows that levels of beta-naphthylamine in urine are significantly elevated in iron foundry workers. Hand molders, finishing workers and truck drivers tended to have the highest levels. Concerning alpha-naphthol the highest concentrations were measured in urine from casters and shake-out workers. With regard to epidemiologic studies demonstrating that molders and casters have a higher risk of lung cancer, the present study suggests that the elevated risk may be due to exposure to carcinogenic PAH compounds in iron foundries, particularly in some high-risk work processes, e.g. casting and molding. In addition, the present study suggests that biological monitoring of 1-hydroxypyrene and beta-naphthylamine may be used to estimate the individual exposure, which seems to be correlated with exposure during individual work processes.

2-Naphthylamine↗
PubMed1994

Exposure of iron foundry workers to polycyclic aromatic hydrocarbons: benzo(a)pyrene-albumin adducts and 1-hydroxypyrene as biomarkers for exposure.

Exposure to polycyclic aromatic hydrocarbons (PAHs) in foundry workers has been evaluated by determination of benzo(a)pyrene-serum albumin adducts and urinary 1-hydroxypyrene. Benzo(a)pyrene binding to albumin and 1-hydroxypyrene were quantitatively measured by enzyme linked immunosorbent assay (ELISA) and reverse phase high performance liquid chromatography (HPLC), respectively. 70 male foundry workers and 68 matched controls were investigated. High and low exposure groups were defined from breathing zone hygienic samples, consisting of 16 PAH compounds in particulate and gaseous phase. Mean total PAH was 10.40 micrograms/m3 in the breathing zone, and mean dust adsorbed PAH was 0.15 microgram/m. All carcinogenic PAH was adsorbed to dust. Median benzo(a)pyrene-albumin adduct concentrations (10-90% percentiles) were similar in foundry workers (smokers 0.55 (0.27-1.00) and non-smokers 0.58 (0.17-1.15)) pmol/mg albumin and age matched controls (smokers 0.57 (0.16-1.45) and non-smokers 0.70 (0.19-1.55) pmol/mg albumin). Median 1-hydroxypyrene concentrations were significantly higher (P < 0.0001) in smoking and non-smoking foundry workers (0.022 (0.006-0.075) and 0.027 (0.006-0.164)) mumol/mol creatinine than in smoking and non-smoking controls (0 (0-0.022) and 0 (0-0.010) mumol/mol creatinine). Dose-response relations between total PAH, pyrene, carcinogenic PAHs, and 1-hydroxypyrene for smokers, and polycyclic aromatic hydrocarbons adsorbed to dust for non-smokers are suggested. Exposure to PAHs adsorbed to dust showed an additive effect. There was no correlation between the concentrations of 1-hydroxypyrene and benzo(a)pyrene-albumin adducts. The change in 1-hydroxypyrene over a weekend was also studied. Friday morning median 1-hydroxypyrene concentrations were significantly higher in both smokers and non-smokers (0.021 (0-0.075) and 0.027 (0.06-0.164)) mumol/mol creatinine than Monday morning median concentrations (0.007 (0-0.021) and 0.008 (0-0.021) mumol/mol creatinine). Smoking did not affect the concentrations of 1-hydroxypyrene or benzo(a)pyrene-albumin adducts. These data suggest that 1-hydroxypyrene is a sensitive biomarker for low dose PAH exposure. Exposure to PAHs may be aetiologically related to increased risk of lung cancer in foundry workers.

Adult↗
PubMed1993

Longitudinal study of excretion of metabolites of polycyclic aromatic hydrocarbons in urine from two psoriatic patients.

Coal tar, which is widely used in the treatment of patients with atopic dermatitis, chronic eczema, and psoriasis, contains a large amount of polycyclic aromatic hydrocarbons (PAH). Some of the PAH compounds are known either to be carcinogenic or to potentiate the effects of other carcinogenic substances. In the present study, the excretion patterns of 1-hydroxypyrene (metabolite of pyrene) and alpha-naphthol (metabolite of naphthalene) in urine were studied in 2 patients, both treated once a day with coal tar pitch covering more than 50% of the skin. After 1 week of treatment, the concentration of both alpha-naphthol and 1-hydroxypyrene increased approximately 100 times. However, the concentration after 3 weeks of treatment was decreased to approximately the concentration measured before initiation of the treatment, even though the patients were coal tar-treated with unchanged intensity. The measured concentrations of alpha-naphthol and 1-hydroxypyrene in the urine of the 2 patients exceeded by order of magnitude the levels measured in the urine of occupationally exposed workers, and in view of the present study, epidemiological studies are needed to clarify to what extent coal tar treatment results in an increased risk of skin cancer, and e.g. bladder cancer.

Adult↗
PubMed1992

Polycyclic aromatic hydrocarbons in air samples of meat smokehouses.

In a screening programme nine Danish meat smokehouses were randomly selected for measurements on concentration of airborne polycyclic aromatic hydrocarbons (PAH). A total of 23 stationary air samples were collected during the entire working period of the kiln either above the kiln doors or approximately 2 m in front of the kiln doors (i.e. total exposure on the day of sampling). Three of these samples had a PAH content below the detection limit of the highly sensitive assay employed. Furthermore, eight personal air samples were collected during the periods of tending the kiln (i.e. peak exposure measurement). Three of these samples were below the detection limit. Total airborne PAH concentration of the stationary air samples calculated as the sum of the concentration of 16 selected PAH compounds, was in general far lower than the total airborne PAH concentration measured in the same manner in smokehouses curing fish (Nordholm et al., 1986). In contrast to the study on PAH exposure in smokehouses curing fish, the present study revealed no significant difference between total PAH content in air samples collected above the kilns compared with samples collected approximately 2 m in front of the kiln doors. Calculation of the relative content of the individual PAH compounds in the stationary air samples collected in meat smokehouses showed naphthalene to be the major compound in (70% +/- 26% of total PAH), whereas the relative content of carcinogenic PAH compounds in average represented 4.0% of the total PAH content. However, only approximately 15% of the stationary air samples with detectable content of total PAH contained detectable amounts of carcinogenic PAH compounds. Hence it was concluded that PAH exposure during cold meat curing might be considered a limited health hazard compared with PAH exposure during hot fish curing.

Air Pollutants, Occupational↗
PubMed1992

Determination of 2-naphthylamine in urine by a novel reversed-phase high-performance liquid chromatography method.

A high-performance liquid chromatographic method for the determination of 2-naphthylamine in urine using fluorescence detection was developed. The method validation analysis showed the method to be in analytical control, i.e. the distribution of the difference between the observed and true values of the method evaluation samples did not deviate significantly from the normal distribution. The recovery of the method was 85%. The entire run time of chromatography was 10 min using isocratic elution (acetonitrile-water, 35:65), and the retention time for 2-naphthylamine was 5.8 min. The relative short time of analysis in combination with the low limit of detection (0.272 nmol/l) makes the method potentially applicable for surveillance of occupational and environmental exposure to 2-nitronaphthalene. The developed method is presently used for measurement of 2-naphthylamine in urine samples from workers employed at factories, characterized by a low airborne exposure level of polycyclic aromatic hydrocarbons, i.e. in general less than 25 micrograms/m3. The urine samples of exposed workers (n = 95) showed a 2-naphthylamine range of up to 9.4 nmol/l, whereas unexposed control individuals (n = 114) showed a range of up to 0.87 nmol/l.

2-Naphthylamine↗
PubMed1992

Do drop-outs differ from successfully treated obsessive-compulsives?

The most common reasons given by patients for dropping out of treatment are: environmental constraints, dissatisfaction with services and that they no longer need help. In this study two groups of patients suffering from obsessive-compulsive disorders are compared. The drop-outs' reasons for terminating treatment are compared with the comments of patients who completed the therapy successfully. Drop-outs differ from successfully treated OCD's in five respects: they appear to be less obsessive-compulsive; they have more discongruent treatment expectations; they are more critical of the therapist; they experience less anxiety in carrying out homework assignments; they less frequently come under pressure from people close to them.

Adaptation, Psychological↗
PubMed1992

An epidemiologic study of neural tube defects: Delta County, Michigan, 1969-1988.

We determined the incidence of neural tube defects (anencephaly, spina bifida, hydrocephalus) in a rural county in the Upper Peninsula of Michigan because several local physicians perceived that the incidence in this area might be high. To assure that all neural tube defects that occurred were noted, data for the study were collected from hospital birth-log books, patient records of all neural tube defect births, all stillbirth records, and from records of babies transferred to other regional hospitals. A reference group consisting of 10% of all nonneural tube defect births during the 20 years of the study was selected at random and used to make comparisons to the case group. During the twenty-year period 1969-1988, the incidence of neural tube defects (NTDs) was found to be 2.09 per 1000 total births. The incidence of anencephaly was 1.05/1000; of spina bifida, 0.56/1000; and for hydrocephalus, 0.48/1000. Seasonal variations by month of conception were noted for anencephaly and spina bifida, confirming previous findings in the literature. Study results showed that between 1972 and 1976 there was a cluster of NTDs, but the NTD incidence was not statistically different from what might be expected over a twenty-year period. The incidence of NTDs in Delta County was found to be normal for this part of North America. The results of this study indicate that physicians should be cautious when attempting to interpret rare events, which often occur in clusters, leaving the impression that their incidence is excessive.

Adult↗
PubMed1991

Correlation of levels of volatile versus carcinogenic particulate polycyclic aromatic hydrocarbons in air samples from smokehouses.

In the present study, data on the concentration of polycyclic aromatic hydrocarbons (PAH) in air samples from fish smokehouses (Nordholm et al. 1986) and meat smokehouses (Hansen et al. submitted for publication) were used to analyze the extent to which six different volatile PAH compounds could function as markers for the total concentration of six different carcinogenic particulate PAH compounds. Although a significant positive correlation was observed between the concentration of each of six volatile compounds and the total concentration of carcinogenic PAH compounds, a particularly good correlation was observed for phenanthrene, anthracene, fluoranthene and pyrene. Calculations of the sensitivity, specificity, positive predictive value and negative predictive value of these potential markers revealed that naphthalene and phenanthrene exhibited the highest sensitivity as markers for total carcinogenic PAH compounds in air samples from smokehouses, whereas fluoranthene and pyrene displayed the highest specificity. However, when the applicability of the six markers was tested on air samples from iron foundries, only naphthalene and pyrene were useful as markers for the carcinogenic compounds. The present study indicates that naphthalene and pyrene might function as markers for carcinogenic PAH compounds, that are present at low concentrations and are therefore difficult and time-consuming to measure directly.

Air Pollutants, Occupational↗
PubMed1991

Validation of a high-performance liquid chromatography/fluorescence detection method for the simultaneous quantification of fifteen polycyclic aromatic hydrocarbons.

A high-performance liquid chromatography/fluorescence method using multiple wavelength shift for simultaneous quantification of different PAH compounds was developed. The new method was superior to the methods of DONG and GREENBERG [J. Liquid Chromatogr. 11, 1887-1905 (1988)] and WISE et al. [Polycyclic aromat. Hydrocarb. (in press)] with respect to sensitivity of detection of the majority of 15 PAH compounds, and in particular of naphthalene, acenaphthene, fluorene and benzo(b)fluoranthene. The method of validation analysis employed showed that the new method is in statistical balance meaning that no systematic errors, and only small unsystematic errors, could be demonstrated. Furthermore, the method had a good reproducibility and a high sensitivity.

Air Pollutants, Occupational↗