Correction: Effect of the orientation and fluid flow on the accumulation of organotin compounds to Chemcatcher passive samplers.

Correction for 'Effect of the orientation and fluid flow on the accumulation of organotin compounds to Chemcatcher passive samplers' by H. Ahkola et al., Environ. Sci.: Processes Impacts, 2015, 17, 813-824, https://doi.org/10.1039/C4EM00585F.

Effect of the orientation and fluid flow on the accumulation of organotin compounds to Chemcatcher passive samplers.

Monitoring of harmful substances in an aquatic environment is based on spot sampling which is the only sampling technique accepted by environmental authorities in the European Union. Still the implementation of the European Union Water Framework Directive (WFD) requires novel sampling tools for monitoring priority pollutants since their concentrations in natural waters can often remain below the limit of detection when using the conventional spot sampling method. However, this does not necessarily mean that the pollutant is not present in the aquatic environment. Many chemicals that are considered to be harmful are bioaccumulative and can affect, e.g., reproduction of aquatic organisms even at very low concentration levels. Also the timing is crucial since with spot sampling the pulse of harmful substances can easily be missed. Passive samplers collect the compounds for a certain amount of time which allows the concentrations in the sampler to rise to the measurable level where they are easy to detect. Organotin compounds (OTCs) have been widely used as plastic stabilizers and antifouling agents in ship paints and in many industrial processes. Among the OTCs, tributyltin is listed as a WFD priority substance. In this study a small-scale flow simulation around the Chemcatcher passive sampler was performed to visualize the flow streamlines in the vicinity of the sampler and to study the pressure experienced by the receiving phase in different sampler positions. With laboratory experiments the sampling rates for each OTC were determined and the effect of the flow velocity and sampler orientation on the accumulation of OTCs is discussed. The pressure changes were observed on the surface of the receiving phase in simulations with varying sampler orientations. Despite that, the laboratory experiments discovered no difference in the accumulation of compounds when varying the sampler orientation. The concentrations of OTCs in the surrounding water calculated from the passive sampling results were equivalent to the spot sampling ones. Hence, the Chemcatcher passive sampler provides a practical tool for the implementation of WFD.

A correlation of flux through a silicone membrane with flux through hairless mouse skin and human skin in vitro.

The maximum fluxes of 32 prodrugs and parabens through polydimethylsiloxane membranes from water (EXP log J(MPAQ)) have been correlated with the maximum flux of the same prodrugs and parabens through hairless mouse skin from water (EXP log J(MMAQ)): EXP log J(MMAQ)=0.608 EXP log J(MPAQ)-0.636, r(2)=0.743. The average of the absolute values for the differences between the EXP log J(MMAQ) and the log J(MMAQ) calculated from EXP log J(MPAQ) (Delta log J(MMAQ)) was 0.227 log units. Similarly the maximum fluxes of 11 unrelated permeants through human skin from water (EXP log J(MHAQ)) was correlated with the EXP log J(MPAQ) for the same permeants: EXP log J(MHAQ)=0.516 EXP log J(MPAQ)-0.922, r(2)=0.82 and Delta log J(MHAQ)=0.252 log units. Since the best fit of the databases for EXP log J(MPAQ), log J(MMAQ) and log J(MHAQ) was to the Roberts-Sloan (RS) model, and the dependency of RS on a balance in lipid and aqueous solubility for optimization of topical delivery has been established, the present correlation suggests that the flux through a silicone can be used to predict flux through mouse or human and that the physicochemical properties that lead to optimized flux through one membrane will lead to optimized flux through the others.

A comparison of the fit of flux through hairless mouse skin from water data to three model equations.

Data for the delivery of total species containing parent drugs from water through hairless mouse skin by prodrugs, logJ(MMAQ), has been fitted to the Roberts-Sloan, RS, the Kasting-Smith-Cooper, KSC, and Magnusson-Anissimov-Cross-Roberts, MACR, equations. The RS model which contains a parameter for the dependence of flux on solubility in water, S(AQ), as well as solubility in the lipid isopropyl myristate, S(IPM), gave the best fit: logJ(MMAQ)=-2.30+0.575 logS(IPM)+0.425 logS(AQ)-0.0016MW, r(2)=0.903. The values for the coefficients to the parameters are quite similar to those obtained when the RS model was fit to flux of solutes from water through human skin, logJ(MHAQ). There was no trend in predicting the under or over-performance of prodrugs based on their fit to the RS model and whether they were more or less soluble than their parent drugs. There was an inverse dependence of logJ(MMAQ) on partition coefficients or permeability coefficients similar to that observed for logJ(MHAQ). The similarities in trends for results for logJ(MMAQ) and logJ(MHAQ) suggests that design directives obtained from mouse skin can be extended to design new prodrugs or select new drugs for delivery through human skin.

Self-reported health, illness, and self-care among finnish physicians: a national survey.

BACKGROUND: Physicians' health problems have been discussed mainly in relation to substance abuse and psychiatric disorders. In this study, the prevalence of common chronic diseases and their treatment were determined. OBJECTIVE: To find differences in self-reported health status, amount of sick leave, and the use of health services among physicians according to sex and specialty. Data were also compared with those of the total employed population. DESIGN AND SETTING: Cross-sectional postal questionnaire survey in Finland. PARTICIPANTS AND METHODS: A random sample of licensed physicians younger than 66 years (n = 4477) was randomly selected from the register of the Finnish Medical Association. A total of 3313 physicians (74%) responded. MAIN OUTCOME MEASURES: Perceived health, prevalence of diseases, self-treatment of diseases, amount of sick leave, and medical consultations. RESULTS: Female physicians assessed their health as being better than other female employees and had used health services and had been on sick leave more often than their male colleagues. Male physicians assessed their health as being equal to that of other men. Both female and male physicians had fewer sick leave than other employees. However, physicians-especially men-reported many common chronic illnesses as often or more often than other employees. Physicians had consulted other medical professionals less often than other employees, and they primarily self-treated their illnesses. Of the specialties, psychiatrists had used health services and had been on sick leave more often than other physicians. CONCLUSION: This study indicates that the usual form of care of physicians' diseases is self-treatment and "working through" illnesses. Arch Fam Med. 2000;9:1079-1085

Serum lipids and apolipoprotein E phenotypes in identical twins reared apart.

Lipid and lipoprotein metabolism is controlled by genes, the environment and the gene environment interaction. We studied monozygotic twin pairs reared apart (MZA) and an age sex matched group of twins reared together (MZT) to evaluate the effects of the genotype and the rearing environment on lipids. The intraclass correlations for low density lipoprotein (LDL) cholesterol were 0.21 and 0.50 for the MZA and MZT groups, respectively, suggesting that the rearing environment possibly had an impact on the variability in LDL cholesterol later in life. The intraclass correlations for total cholesterol (0.26 and 0.47 for the MZA and MZT groups, respectively) reflected those for LDL cholesterol. The intraclass correlations for high density lipoprotein (HDL) cholesterol did not show any difference between the twin groups, suggesting that the rearing environment does not have major long-term effects on the variability of HDL levels. The intrapair differences for LDL cholesterol were smallest in the twins heterozygous for the apolipoprotein E allele epsilon2 (E2/3 and E2/4 phenotypes), intermediate in the pairs with the common E3/3 phenotype and enhanced in the pairs with E4/3 phenotype. To conclude, these data suggest that the rearing environment may play a role in the variability of LDL cholesterol levels, although variance difference between MZAs and MZTs, and the small number of available monozygotic twins reared apart limits the generalizability of the results.

Neurological signs in relation to cancer in patients with asbestosis.

OBJECTIVE: To chart the subtle neurological abnormalities in patients with asbestosis relative to possible development of cancer. METHODS: In 1979-81 a standardised neurological examination was made of 115 patients with asbestosis who carried a high risk of occupational cancer and their cancer morbidity was analysed 15 years later. RESULTS: Slight disturbances of unknown aetiology were found in the central nervous system (CNS) of 33 and in the peripheral nervous system (PNS) of 41 patients. Of these 17 had disturbances of both the CNS and PNS. This cohort was followed up to the end of 1994. During this time 47 of the patients developed cancer. Statistical analyses showed that disturbances of the CNS such as psycho-organic syndrome, cerebellar dysfunction, and motor disturbances of unknown origin were significantly associated with cancer, whereas no such association was found for peripheral neuropathy. Interaction between the radiological progression of asbestosis and disturbances of the CNS was an even stronger predictor of cancer. CONCLUSIONS: It seems that slight disturbances of the CNS are predictors of development of cancer. Whether or not these disturbances are manifestations of involvement of a paraneoplastic nervous system or some factor associated with progression of asbestosis remains open.

Exposure, skin protection and occupational skin diseases in the glass-fibre-reinforced plastics industry.

A total of 100 workers, 86 from the glass-fibre-reinforced plastics (GRP) industry, 11 from polystyrene production and 3 from polyester resin coating manufacture, were examined for occupational skin hazards and for evaluation of skin protection. The workers had been exposed to many chemicals. Those working in the GRP industry had also been exposed to glass fibre and to dust produced by finishing work. 94% used protective gloves. 22 workers, all employed in the GRP industry, had contracted occupational skin disorders. 6 had allergic and 12 irritant contact dermatitis. 4 workers had an accidental injury caused by a peroxide catalyst, fire, hot air and constant mechanical friction. Allergic dermatoses were due to natural rubber (latex) (4 cases) in protective gloves, phenol-formaldehyde resin (1 case) and cobalt naphthenate (1 case). Irritant hand dermatoses (5 cases) were caused by the combined hazardous effect of unsaturated polyester or vinyl ester resins, organic solvents, glass fibre and dust from finishing work on the skin. Other cases of irritant dermatoses (7 cases) were due to the dust, promoted by mechanical friction of clothes. Skin disorders in the GRP industry were common (26%) but the symptoms were mild and only 3 patients had been on sick leave because of occupational skin disease.

Effects of recombinant alpha-2b-interferon therapy in patients with progressive MS.

The effects of systemic recombinant interferon-alpha-2b were studied in 6 carefully selected patients with progressive multiple sclerosis. 3.0 million IU were given as daily subcutaneous injections for 6 months, 5 patients showed worsening disability, and in 4 of them new or enlarged lesions were detected in MRI. In one patient no change in disability was found; his MRI showed regressed changes. The mean progression index during the treatment was significantly higher (p < 0.02) than during the previous 2 to 3 years' period of continuous progression. The frequency of peripheral blood natural killer (CD16+) cells declined significantly 3 months during the treatment, but returned to the pretreatment values after termination the treatment. An increase of intrathecal IgG synthesis and oligoclonal bands was demonstrated in 4 and 3 patients, respectively. Our experience suggests that long-term recombinant IFN-alpha-2b treatment may activate the immunological process of MS.

Nervous system effects of occupational exposure to styrene: a clinical and neurophysiological study.

Quantitative EEG of 99 workers occupationally exposed to styrene was analyzed and compared to exposure parameters. All of the workers came from reinforced plastics industry. The workplaces and factories were previously evaluated, and the exposure levels were known rather accurately. The exposure information form workplaces and the individual exposure data were combined to form an Exposure Index, which reliably reflected long-term exposure to styrene in various occupational settings. All of the subjects underwent careful medical, neurological, and neurophysiological examinations. Quantitative EEG was recorded from 19 channels and analyzed for absolute and relative power, asymmetry, coherence, frequency distribution, and statistical normative database comparisons (Neurometrics). The EEG data showed a significant increase of abnormal EEG classifications in workers with higher exposure. When the workers were divided into two groups, based on the exposure data, those with higher exposure had higher absolute EEG power in alpha and beta bands in the frontotemporal regions of the brain. The findings indicate that abnormalities in cerebral function can be demonstrated even with relatively low mean exposure levels. It is concluded that the efforts to lower the administrative hygienic levels of styrene have been in the right direction.

Acute effects of m-xylene inhalation on body sway, reaction times, and sleep in man.

Nine male volunteers were exposed to either a constant or a fluctuating exposure pattern of m-xylene with a time-weighted average exposure concentration of 200 ppm in both cases. The subjects remained sedentary throughout the exposure, or the exercised at 100 W for 10 min at the beginning of the morning and the afternoon sessions. In another experiment, 12 sedentary male volunteers were exposed to a fixed 200 ppm of m-xylene. The effects of m-xylene on body sway, reaction time performance, and overnight sleep were measured. Body balance was stabilized after exposure to the peaks of 400 ppm of m-xylene in both sedentary and exercising subjects. Simple visual reaction times were prolonged after the peak exposures at rest whereas auditive choice reaction times were prolonged after peaks combined with exercise. Exposure to m-xylene at a constant level of 200 ppm did not affect the ratio of "active" to "quiet" sleep in the volunteers as measured with the static charge sensitive bed recording, but decreased slightly the number of body movements in bed. On the next morning no changes were found in body sway and reaction time performance as compared to the morning before exposure.

Neurotoxicity in workers exposed to styrene.

Quantitative electroencephalography (EEG) for 99 workers exposed to styrene in the reinforced-plastics industry was analysed and compared with exposure parameters. The work places and factories from which the subjects were selected had been evaluated previously, and exposure levels were known relatively accurately. That information and data on individual exposures were combined to create an exposure index, which reliably reflected long-term exposure to styrene in various occupational settings. All of the subjects underwent careful medical and neurophysiological examinations. Quantitative EEG was recorded on 19 channels and analysed for absolute and relative power, asymmetry, coherence, frequency distribution, and statistical normative data base comparisons (neurometrics). When the workers were divided into three groups on the basis of exposure, workers with the highest exposure had significantly more EEGs classified as abnormal and had higher absolute EEG power in alpha band in the fronto-temporal regions of the brain. The findings indicate that abnormalities can occur in cerebral function even after relatively low mean exposures. We conclude that the efforts to lower regulatory hygienic levels of styrene are justified.

Neurotoxic syndromes and occupational exposure to solvents.

Neurotoxic syndromes due to occupational solvent exposure present a worldwide health problem, the magnitude of which varies from country to country. Apart from the relatively clear-cut exposure-effect relationships in acute solvent intoxications, those caused by long-term, low-level occupational exposure to solvents are more difficult to detect. Controversial opinions and even debate are frequently encountered in literature on this matter. This is partly due to differences in neurobehavioral methods used, partly to difficulties in obtaining accurate information about exposure. These effects can be studied in humans using biochemical, clinical, and epidemiological methods. It is thus quite conceivable that direct comparison of the results obtained by different methods is not always possible. Moreover, exposure to a variable mixture of solvents is frequent in an occupational setting which is problematic from the toxicological point of view. The clinical pictures of "chronic" occupational solvent intoxications are, with few exceptions, quite nonspecific in nature and share several common features regardless of the underlying chemical exposure. The development of manifest disease is insidious and high interindividual variation of symptoms and signs exists. Some solvents cause primarily peripheral neuropathy. Deterioration in many psychological and neurophysiological functions can be seen. The most common subjective symptoms of solvent intoxication are headache, tiredness, memory disturbances, and dizziness. Clinical findings comprise signs of the central nervous system depression (psychoorganic syndrome, tiredness), dizziness, disturbances in coordination, and general neurasthenic signs. From the clinical point of view, it is important to define the criteria for a diagnosis. In different countries the diagnostic criteria for solvent intoxication may vary considerably, which provides additional difficulties in interpreting the results of studies in this field.