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Biomedical subjects

Lennart Hardell

Publications and source records attributed to Lennart Hardell.

At least 19 recordsLinked to original sources

Secret ties to industry and conflicting interests in cancer research.

BACKGROUND: Recently it was reported that a Swedish professor in environmental health has for decades worked as a consultant for Philip Morris without reporting his employment to his academic employer or declaring conflicts of interest in his research. The potential for distorting the epidemiological assessments of hazard and risk through paid consultants, pretending to be independent, is not exclusive to the tobacco industry. METHODS: Documentation is drawn from peer reviewed publications, websites, documents from the Environmental Protection Agency, University reports, Wellcome Library Special Collections and the Washington Post. RESULTS: Some consulting firms employ university researchers for industry work thereby disguising industry links in the income of large departments. If the industry affiliation is concealed by the scientist, biases from conflicting interests in risk assessments cannot be evaluated and dealt with properly. Furthermore, there is reason to suspect that editors and journal staff may suppress publication of scientific results that are adverse to industry owing to internal conflict of interest between editorial integrity and business needs. CONCLUSIONS: Examples of these problems from Sweden, UK, and USA are presented. The shortfalls cited in this article illustrate the need for improved transparency, regulations that will help curb abuses as well as instruments for control and enforcement against abuses.

Biomedical Research↗

Tumour risk associated with use of cellular telephones or cordless desktop telephones.

BACKGROUND: The use of cellular and cordless telephones has increased dramatically during the last decade. There is concern of health problems such as malignant diseases due to microwave exposure during the use of these devices. The brain is the main target organ. METHODS: Since the second part of the 1990's we have performed six case-control studies on this topic encompassing use of both cellular and cordless phones as well as other exposures. Three of the studies concerned brain tumours, one salivary gland tumours, one non-Hodgkin lymphoma (NHL) and one testicular cancer. Exposure was assessed by self-administered questionnaires. RESULTS: Regarding acoustic neuroma analogue cellular phones yielded odds ratio (OR) = 2.9, 95 % confidence interval (CI) = 2.0-4.3, digital cellular phones OR = 1.5, 95 % CI = 1.1-2.1 and cordless phones OR = 1.5, 95 % CI = 1.04-2.0. The corresponding results were for astrocytoma grade III-IV OR = 1.7, 95 % CI = 1.3-2.3; OR = 1.5, 95 % CI = 1.2-1.9 and OR = 1.5, 95 % CI = 1.1-1.9, respectively. The ORs increased with latency period with highest estimates using > 10 years time period from first use of these phone types. Lower ORs were calculated for astrocytoma grade I-II. No association was found with salivary gland tumours, NHL or testicular cancer although an association with NHL of T-cell type could not be ruled out. CONCLUSION: We found for all studied phone types an increased risk for brain tumours, mainly acoustic neuroma and malignant brain tumours. OR increased with latency period, especially for astrocytoma grade III-IV. No consistent pattern of an increased risk was found for salivary gland tumours, NHL, or testicular cancer.

Journal Article↗

Pooled analysis of two case-control studies on use of cellular and cordless telephones and the risk for malignant brain tumours diagnosed in 1997-2003.

OBJECTIVES: To study the use of cellular and cordless telephones and the risk for malignant brain tumours. METHODS: Two case-control studies on malignant brain tumours diagnosed during 1997-2003 included answers from 905 (90%) cases and 2,162 (89%) controls aged 20-80 years. We present pooled analysis of the results in the two studies. RESULTS: Cumulative lifetime use for >2,000 h yielded for analogue cellular phones odds ratio (OR)=5.9, 95% confidence interval (CI)=2.5-14, digital cellular phones OR=3.7, 95% CI=1.7-7.7, and for cordless phones OR=2.3, 95% CI=1.5-3.6. Ipsilateral exposure increased the risk for malignant brain tumours; analogue OR=2.1, 95% CI=1.5-2.9, digital OR=1.8, 95% CI=1.4-2.4, and cordless OR=1.7, 95% CI=1.3-2.2. For high-grade astrocytoma using >10 year latency period analogue phones yielded OR=2.7, 95% CI=1.8-4.2, digital phones OR=3.8, 95% CI=1.8-8.1, and cordless phones OR=2.2, 95% CI=1.3-3.9. In the multivariate analysis all phone types increased the risk. Regarding digital phones OR=3.7, 95% CI=1.5-9.1 and cordless phones OR=2.1, 95% CI=0.97-4.6 were calculated for malignant brain tumours for subjects with first use use <20 years of age, higher than in older persons. CONCLUSION: Increased risk was obtained for both cellular and cordless phones, highest in the group with >10 years latency period.

Brain Neoplasms↗

Perfluorinated chemicals in relation to other persistent organic pollutants in human blood.

In order to evaluate blood levels of some perfluorinated chemicals (PFCs) and compare them to current levels of classical persistent organic pollutants (POPs) whole blood samples from Sweden were analyzed with respect to 12 PFCs, 37 polychlorinated biphenyls (PCBs), p,p'-dichlorodiphenyl-dichloroethylene (DDE), hexachlorobenzene (HCB), six chlordanes and three polybrominated diphenyl ethers (PBDEs). The median concentration, on whole blood basis, of the sum of PFCs was 20-50 times higher compared to the sum of PCBs and p,p'-DDE, 300-450 times higher than HCB, sum of chlordanes and sum of PBDEs. Estimations of the total body amount of PFCs and lipophilic POPs point at similar body burdens. While levels of for example PCBs and PBDEs are normalized to the lipid content of blood, there is no such general procedure for PFCs in blood. The distributions of a number of perfluorinated compounds between whole blood and plasma were therefore studied. Plasma concentrations were higher than whole blood concentrations for four perfluoroalkylated acids with plasma/whole blood ratios between 1.1 and 1.4, whereas the ratio for perflurooctanesulfonamide (PFOSA) was considerably lower (0.2). This suggests that the comparison of levels of PFCs determined in plasma with levels determined in whole blood should be made with caution. We also conclude that Swedish residents are exposed to a large number of PFCs to the same extent as in USA, Japan, Colombia and the few other countries from which data is available today.

Adult↗

Increased incidence of malignancies in Sweden after the Chernobyl accident--a promoting effect?

BACKGROUND: After the Chernobyl accident in 1986, as much as 5% of the released caesium-137 was deposited in Sweden due to a heavy rainfall 2 days after the event. A study of increased incidence of malignancies was initiated after the accident. METHODS: The cohort included 1,137,106 inhabitants who were 0-60 years old in 1986 and lived in 8 counties of Sweden with the highest fallout of caesium-137. With the dwelling coordinate, GIS-technique and a digital map on caesium-137, each individual was matched for the exposure. Adjustments were made for several potential confounding factors. During the follow-up 33,851 malignancies was recorded 1988-1999. RESULTS: Exposure categories were: 0-8 (reference), 9-23, 24-43, 44-66, 67-84, and > or =85 nGy/hr. The corresponding adjusted Mantel-Haenszel incidence rate ratios for total malignancies during follow-up amounted to 1.000, 0.997, 1.072, 1.114, 1.068, 1.125, respectively. The excess relative risk per 100 nGy/hr with the same adjustments and time period was 0.042 95% confidence limit 0.001;0.084. An excess for thyroid cancer or leukemia could not be ruled out. CONCLUSION: Increased incidence of total malignancies possibly related to the fallout from the Chernobyl accident is seen.

Adolescent↗

Occupational sun exposure and mycosis fungoides: a European multicenter case-control study.

OBJECTIVE: We sought to study the association between occupational sun exposure and mycosis fungoides (MF), a peripheral T-cell lymphoma. SUBJECTS AND METHODS: A European multicenter case-control study including seven rare cases (one being MF) was conducted between 1995 and 1997. From the 118 accepted cases, 104 were interviewed, of which 76 were definite cases. Population controls were selected randomly from the regions of case ascertainment. Information based on occupational experiences was coded according to industry types. A job exposure matrix was created according to the expected exposure to sunlight. RESULTS: Once exposures to aromatic halogenated hydrocarbons were eliminated (odds ratio = 2.3; 95% confidence interval = 0.9-6.2), a high MF risk was associated with exposures to solar radiation. CONCLUSION: It would appear that workers exposed to sunlight have a higher risk of MF. However, this factor is not the only one involved.

Aged↗

Adipose tissue concentrations of persistent organic pollutants and the risk of prostate cancer.

OBJECTIVE: We sought to study the concentrations of certain persistent organic pollutants with endocrine-disrupting properties in cases with prostate cancer and controls with benign prostate hyperplasia. METHODS: Adipose tissue was obtained from 58 cases and 20 controls. RESULTS: The median concentration among controls was used as cut-off in the statistical analysis. In the total material, a greater-than median concentration of PCB congener 153 yielded an odds ratio (OR) of 3.15 and 95% confidence interval (CI) of 1.04-9.54 and one chlordane type, trans-chlordane, yielded OR 3.49 (95% CI = 1.08-11.2). In the group of case subjects with PSA levels greater than the median level of 16.5 ng/mL, PCB 153 was OR 30.3 (95% CI = 3.24-284), hexachlorobenzene OR = 9.84 (95% CI = 1.99-48.5), trans-chlordane OR = 11.0 (95% CI = 1.87-64.9), and the chlordane-type MC6 OR = 7.58 (95% CI = 1.65-34.9). The grouping of PCBs according to structural and biological activity was found to produce significantly increased risks for enzyme and phenobarbital-inducing PCBs and lower chlorinated PCBs in the case group with PSA levels greater than 16.5 ng/mL. CONCLUSIONS: These chemicals might be of etiologic significance but need to be further investigated. The biological relevance of the arbitrary cut-off point of PSA is unclear.

Adipose Tissue↗

High concentrations of organochlorines in a patient with kidney cancer and anorexia-cachexia syndrome.

PURPOSE: To determine persistent organic pollutants in adipose tissue in a patient with kidney cancer. METHODS: Adipose tissue was sampled from the abdominal wall during autopsy of a 75-year old man who had died from a kidney cancer. The concentrations of polychlorinated biphenyls (PCBs), p,p'-dichlorodiphenyltrichloroethane (DDE), hexachlorobenzene (HCB), chlordanes and tetrabromodiphenyl ether (TeBDE) were determined on lipid basis. For comparison results from 29 male population based subjects aged 70-80 years were used. RESULTS: All concentrations except for TeBDE were very high in the patient; sum of PCBs 18 808 ng/g fat (median for controls 997), DDE 14 183 (median for controls 751), HCB 424 (median for controls 46), and sum of chlordanes 2 389 (median for controls 62). The patient lost weight from 80 kg to 48 kg when he died, which may have contributed wholly or partly to the very high concentrations of organochlorines. CONCLUSION: Changes in weight must be recorded in cancer patients and the concentrations of persistent organic pollutants should be normalized to weight. The concentrations in this patient were 10- to almost 40-times higher than in the controls. Such very high concentrations may give clinical symptoms in the final stage of a wasting cancer patient.

Adipose Tissue↗

Pooled analysis of two case-control studies on the use of cellular and cordless telephones and the risk of benign brain tumours diagnosed during 1997-2003.

The use of cellular and cordless telephones and the risk of brain tumours is of concern since the brain is a high exposure area. We present the results of a pooled analysis of two case-control studies on benign brain tumours diagnosed during 1997-2003 including answers from 1,254 (88%) cases and 2,162 (89%) controls aged 20-80 years. For acoustic neuroma, the use of analogue cellular phones gave an odds ratio (OR) of 2.9 and a 95% confidence interval (CI) of 2.0-4.3; for digital cellular phones, OR=1.5; 95% CI=1.1-2.1; and for cordless telephones, OR=1.5, 95% CI=1.04-2.0. The highest OR was found for analogue phones with a latency period of >15 years; OR=3.8, 95% CI=1.4-10. Regarding meningioma, the results were as follows: for analogue phones, OR=1.3, 95% CI=0.99-1.7; for digital phones, OR=1.1, 95% CI=0.9-1.3; and for cordless phones, OR=1.1, 95% CI=0.9-1.4. In the multivariate analysis, a significantly increased risk of acoustic neuroma was found with the use of analogue phones.

Adult↗

In utero exposure to persistent organic pollutants in relation to testicular cancer risk.

Testicular cancer is the most common tumour type in young men. In Sweden the annual age-adjusted incidence increased significantly by 2.4% during the time period 1984-1993 and during 1994-2003 by 1.4%. Exposure to endocrine disrupting chemicals during the foetal period has been postulated to be a risk factor. In this investigation we studied the concentrations of chlorinated biphenyls (PCBs), p,p'-dichlorodiphenyl-dichloroethylene (pp'-DDE), hexachlorobenzene (HCB), chlordanes and polybrominated diphenylethers (PBDEs) in 58 cases with testicular cancer and 61 age-matched controls. Furthermore, case and control mothers were also asked to participate and 44 case mothers and 45 control mothers agreed. No significant differences were found between cases and controls. Case mothers had in general higher concentrations of these chemicals. For the sum of PCBs an odds ratio (OR) = 3.8, 95% confidence interval (CI) = 1.4-10 was calculated using the median concentration for the controls as cut-off value. For HCB OR = 4.4, CI = 1.7-12 and for PBDE OR = 2.5, 95% CI = 1.02-6.0 were obtained, whereas OR was not significantly increased for pp'-DDE and sum of chlordanes. The cases were born during a period with high concentrations of persistent organic pollutants (POPs) in humans. The decline of the increasing incidence of testicular cancer during recent years may reflect decreasing body burden of certain POPs since the 1980s.

Case-Control Studies↗

Use of cellular or cordless telephones and the risk for non-Hodgkin's lymphoma.

OBJECTIVES: To evaluate the use of cellular and cordless telephones as the risk factor for non-Hodgkin's lymphoma (NHL). METHODS: Male and female subjects aged 18-74 years living in Sweden were included during a period from 1 December 1999 to 30 April 2002. Controls were selected from the national population registry. Exposure to different agents was assessed by questionnaire. RESULTS: In total, 910 (91%) cases and 1016 (92%) controls participated. NHL of the B-cell type was not associated with the use of cellular or cordless telephones. Regarding T-cell NHL and >5 year latency period, the use of analogue cellular phones yielded: odds ratio (OR) = 1.46, 95%; confidence interval (CI) = 0.58-3.70, digital: OR=1.92, 95%; CI=0.77-4.80 and cordless phones: OR=2.47; CI=1.09-5.60. The corresponding results for certain, e.g. cutaneous and leukaemia, T-cell lymphoma for analogue phones were: OR=3.41, 95%; CI=0.78-15.0, digital: OR=6.12, 95%; CI=1.26-29.7 and cordless phones: OR=5.48, 95%; CI=1.26-23.9. CONCLUSIONS: The results indicate an association between T-cell NHL and the use of cellular and cordless telephones, however based on low numbers and must be interpreted with caution. Regarding B-cell NHL no association was found.

Adolescent↗

Case-control study of the association between the use of cellular and cordless telephones and malignant brain tumors diagnosed during 2000-2003.

We performed a case-control study on the use of cellular and cordless telephones and the risk for brain tumors diagnosed during 2000-2003. We report the results for malignant brain tumors with data from 317 cases (88%) and 692 controls (84%). The use of analog cellular phones yielded odds ratio (OR) of 2.6 and a 95% confidence interval (CI) of 1.5-4.3, increasing to OR=3.5 and 95% CI=2.0-6.4 with a >10-year latency period. Regarding digital cellular telephones, the corresponding results were OR=1.9, 95% CI=1.3-2.7 and OR=3.6, 95% CI=1.7-7.5, respectively. Cordless telephones yielded OR=2.1, 95% CI=1.4-3.0, and with a >10-year latency period, OR=2.9, 95% CI=1.6-5.2. The OR increased with the cumulative number of hours of use and was highest for high-grade astrocytoma. A somewhat increased risk was also found for low-grade astrocytoma and other types of malignant brain tumors, although not significantly so. In multivariate analysis, all three phone types studied showed an increased risk.

Adult↗

Case-control study on cellular and cordless telephones and the risk for acoustic neuroma or meningioma in patients diagnosed 2000-2003.

We performed a case-control study on the use of cellular and cordless telephones and the risk for brain tumors. We report the results for benign brain tumors with data from 413 cases (89% response rate), 305 with meningioma, 84 with acoustic neuroma, 24 with other types and 692 controls (84% response rate). For meningioma, analogue phones yielded odds ratio (OR) = 1.7, 95% confidence interval (CI) = 0.97-3.0, increasing to OR = 2.1, 95% CI = 1.1-4.3 with a >10-year latency period. Also digital cellular phones and cordless phones increased the risk to some extent. For acoustic neuroma, analogue phones gave OR = 4.2, 95% CI = 1.8-10 increasing to OR = 8.4, 95% CI = 1.6-45 with a >15-year latency period, but based on low numbers. Digital phones yielded OR = 2.0, 95% CI = 1.05-3.8, whereas for cordless phones OR was not significantly increased. In the multivariate analysis, analogue phones represented a significant risk factor for acoustic neuroma.

Adult↗

Development of a solid-phase extraction-HPLC/single quadrupole MS method for quantification of perfluorochemicals in whole blood.

A method for the determination of perfluorooctanesulfonate (PFOS) and perfluorooctanoic acid (PFOA) simultaneously with 10 closely related perfluorochemicals (PFCs) in human whole blood was developed and validated. PFOS and PFOA are used in various applications, for example, as surfactants and plastic additives, and are subject to environmental and health research due to their persistence. The main part of the data on PFCs in human blood is from serum samples, analyzed mainly by ion pair extraction followed by high-performance liquid chromatography (HPLC) and negative electrospray (ESI) tandem mass spectrometry (MS/MS). The analytical method developed here is suitable for human whole blood and involves solid-phase extraction (SPE) and HPLC negative electrospray single quadrupole mass spectrometry (HPLC/ES-MS). A whole blood aliquot was treated with formic acid and extracted on a octadecyl (C18) SPE column. The PFCs were isolated with methanol, and quantification was performed using single quadrupole mass spectrometry and perfluoroheptanoic acid as internal standard. Validation was performed in the range 0.3-194 ng/mL with recovery between 64 and 112% and limit of detection in the 0.1-0.5 ng/mL range for 11 of the 12 PFCs studied. We applied this method to 20 whole blood samples collected in 1997-2000 from the Swedish population in the ages 24-72. Eleven of the 12 PFCs were detected, and they were quantitatively and qualitatively confirmed using triple quadrupole LC/MS/MS analysis. PFOS, perfluorooctanesulfonamide, perfluorohexanesulfonate, PFOA and perfluorononanoic acid were quantified in all samples. In addition, perfluorohexanoic acid, perfluorodecanoic acid, perfluorodecanesulfonate, perfluoroundecanoic acid, perfluorododecanoic acid, and perfluorotetradecanoic acid were detected in some samples. This study shows that SPE and single quadrupole MS can be applied for extraction and quantification of PFCs in human whole blood, resulting in selectivity and low detection limits.

Alkanesulfonic Acids↗

Occupational risks for uveal melanoma results from a case-control study in nine European countries.

OBJECTIVE: Uveal melanoma is a rare disease with poor prognosis and largely unknown etiology. We studied potential occupational risk factors. METHODS: A population based case-control study was undertaken during 1995-1997 in nine European countries using population and colon cancer controls with personal interviews. Occupational exposure to sunlight and artificial UV radiation was assessed with a job exposure matrix. In total, 320 uveal melanoma cases were eligible at pathology review, and 292 cases were interviewed, participation 91%. Out of 3357 population controls, 2062 were interviewed, 61%, and out of 1272 cancer controls 1094 were interviewed, 86%. RESULTS: Using population controls, occupational exposure to sunlight was not associated with an increased risk (RR=1.24, 95% CI=0.88-1.74), while an excess risk found with use of colon cancer controls was attributed to confounding factors. An excess risk in welders was restricted to the French part of the data. Cooks, RR=2.40; cleaners, RR 2.15; and laundry workers, RR=3.14, were at increased risk of uveal melanoma. CONCLUSION: Our study does overall not support an association between occupational sunlight exposure and risk of uveal melanoma. The finding of an excess risk of eye melanoma in cooks in several European countries is intriguing.

Adult↗

Occupational exposures and mycosis fungoides. A European multicentre case-control study (Europe).

OBJECTIVES: Mycosis Fungoides (MF) is a rare disease with an occurrence indicating that occupational exposures may play a role. To estimate the association between MF and occupational exposures as measured by means of an job-exposure matrix (JEM). METHODS: A European multicenter case-control study was conducted from 1995 to 1997 and included seven rare cancers, one of which was MF. Patients between 35 and 69 years of age, diagnosed with MF (n=140), were recruited and the diagnoses were checked by a reference pathologist who classified 83 cases as definite, 35 cases as possible and 22 cases as not accepted. Among the 118 accepted cases, 104 cases were interviewed, of which 76 were definite cases. We selected population controls and colon cancer controls to serve all seven case groups. Altogether 833 colon cancer controls and 2071 population controls were interviewed. Based on the reported occupational experiences, a team of industrial hygiene specialists identified five potential exposures and developed an JEM. This JEM was used to estimate the odds ratios (OR) for MF as a function of these exposures. The JEM included aromatic and/or halogenated hydrocarbons (AAHs), chrome (VI) and its salts, electromagnetic radiations, silica and pesticides. RESULTS: Exposures to AHHs (OR 6.3, C.I 2.4-16.7 for male) were associated with a high MF risk. CONCLUSIONS: The study supports the hypothesis that some MFs have an occupational etiology but only a small fraction of exposed workers are apparently susceptible since the disease is so rare.

Adult↗