Mortality experience of male workers at a UK tin smelter

BACKGROUND

Between 1937 and 1991, Capper Pass and Sons Limited operated a tin smelter complex in North Humberside, UK, at which employees were potentially exposed to a number of substances, including lead, arsenic, cadmium and natural series radionuclides. Decommissioning and site clearance continued until 1995. Between 1967 and 1995 the company was a subsidiary of Rio Tinto plc.

AIMS

The aim was to identify any significant excess, or deficits, in mortality among former employees that might be attributable to factors associated with occupation.

METHODS

We defined a cohort of 1462 males who had been employed for at least 12 months between 1/11/1967 and 28/7/1995, followed-up through to 31/12/2001. The mortality of the cohort was compared against that expected for both national and regional populations.

RESULTS

Mortality from all causes and all cancers did not differ from that expected. Mortality from ischaemic heart disease showed a deficit and mortality from lung cancer showed a statistically significant excess. Mortality from smoking related diseases other than lung cancer showed a non-significant deficit.

CONCLUSIONS

The pattern of lung cancer mortality is consistent with the hypothesis that the risk of lung cancer has been enhanced by occupational exposure to one or more carcinogens, the effect of which diminishes with time since exposure. The deficit in ischaemic heart disease may be attributed to a protective effect from manual labour. The results provide no evidence for attribution of other excess or deficits in mortality to factors associated with employment.

Mortality and cancer morbidity experience of female workers at the British Nuclear Fuels Sellafield plant, 1946-1998

BACKGROUND

Studies of nuclear workers have focused mainly on the experience of male workers. To date, little has been published specifically on the experience of female workers in the nuclear industry.

METHODS

We report on the mortality, cancer morbidity, and tracing experience of the 6,376 females ever employed at the British Nuclear Fuels Ltd. plant at Sellafield to the end of 1998. These workers have accumulated 142,337 person-years of experience.

RESULTS

Radiation workers were exposed to low doses of radiation. No statistically significant associations were noted between mortality or cancer morbidity and cumulative assessed organ-specific internal plutonium dose or cumulative external whole body radiation dose overall, or for any of the individual disease groupings examined. The power of the study was insufficient to detect the risks indicated in other radiation studies.

CONCLUSION

This study offers reassurance that there is no detrimental effect on the health of the female workers from occupational exposures at Sellafield. Am. J. Ind. Med. 44:653-663, 2003.

The accessibility of computer-based health information for patients: kiosks and the web

The Internet is a rich source of health information but it is not as accessible as many claim. This paper brings together three projects to illustrate technical and cost barriers and some options to overcome them. (1) A survey amongst a representative sample of 180 patients in rural Spain showed a marked age gradient in computer access. None over the age of 50 had, and less than 10% planned, access to the Internet whereas a quarter were prepared to use health centre based touchscreen kiosks. (2) Half the commonly used search engines did not include the two most relevant websites for Glasgow colorectal cancer patients in the first ten documents listed, showing the difficulty facing patients in finding relevant information. Selection of information would help patients avoid being overwhelmed with information. (3) One method to improve accessibility is to download websites to kiosks but two projects showed that considerable work is required to reformat the information. Public access computing, such as kiosks, could help make the Internet more accessible. We discuss whether Web sites which structure their information according to method of access, place and person provide a way forward.

Trends in hospitalization and mortality from rotavirus disease in New Zealand infants

BACKGROUND

Rotavirus illness is associated with significant morbidity and mortality worldwide. We have examined trends in diarrheal disease in New Zealand children to determine the disease burden attributable to rotavirus and to estimate the proportion of hospitalizations preventable by vaccination.

METHODS

Hospital admissions data and laboratory records for 1994 to 1996, were obtained for children 0 to 4 years at four sites (serving -60% of the New Zealand population). Rotavirus disease burden was estimated using combined admissions and laboratory data. Severity of disease was estimated in a sample of 150 hospitalizations for rotavirus diarrhea, and the proportion of vaccine-preventable admissions was extrapolated. Mortality attributed to diarrheal causes was determined from national records for 1974 to 1993.

RESULTS

Between 1994 and 1996, 4436 children <5 years of age were hospitalized with diarrhea (1047/100000 children per year). Admissions associated with rotavirus were estimated at 1522 to 1535 (315 to 362/100000 annually). Infants between 6 and 17 months were most commonly affected (42% of all cases). More male children than female children were hospitalized (P < 0.001) and mean length of stay was calculated as 1.51 days (SD 2.35). Disease severity scoring revealed that 61.3 and 38.0% of admissions reviewed were severe and very severe, respectively. Deaths from diarrheal causes numbered 138 among children 0 to 4 years old for the 20-year period 1974 to 1993, with 18 deaths occurring between 1984 and 1993 (10 years).

CONCLUSION

Current vaccines control severe disease, suggesting that 72% of cases reviewed would be eligible for prevention. A full cost effectiveness analysis is required to demonstrate anticipated benefits of vaccination.

Extracapsular cataract surgery in Vietnam: a 1 year follow-up study

PURPOSE

Unoperated cataract is the leading cause of blindness in the developing world. Many developing countries now use extracapsular cataract extraction (ECCE) with intra-ocular lens insertion (IOL) in their cataract blindness-prevention programmes. To date, little research has been directed at visual outcomes and complication rates of ECCE/IOL surgery in developing countries.

METHODS

We conducted a follow-up study of 155 eyes approximately 12 months after ECCE/IOL surgery by eight local eye surgeons in Central Vietnam. We report the findings for the 144 eyes (93%) successfully reviewed. All subjects underwent manual ECCE with insertion of a three-piece posterior chamber IOL. All eyes were also assessed for the presence and severity of posterior capsule opacification (PCO) using a newly developed grading system.

RESULTS

Overall, 110 eyes (75%) had uncorrected visual acuities > or = 6/24 and 107 eyes (74%) had best spherically corrected visual acuities > or = 6/18. Some degree of PCO was found in 40% of eyes, but was graded as visually significant in only 4% of eyes. No major sight-threatening complications were noted. A portable neodymium:yttrium aluminium garnet (Nd:YAG) laser was used to perform capsulotomies on all eyes with visually significant PCO. There were no laser complications noted.

CONCLUSIONS

At approximately 1 year after ECCE/IOL, the visual outcomes for subjects in this cohort were favourable and complication rates were low. Posterior chamber opacification was not a major cause of vision impairment in this cohort. Portable Nd:YAG lasers may provide an effective solution to the problem of visually significant PCO occurring in developing countries as a late complication of extracapsular surgery. These findings support an increasing role for ECCE/PCIOL surgery by trained local eye surgeons in developing countries.

Modern surgery for global cataract blindness: preliminary considerations

Unoperated cataract in the developing world remains ophthalmology's major unsolved problem. Recent developments have brought into question the assumptions of those who have thought that extracapsular surgery with implantation of a posterior chamber intraocular lens is an unrealistic approach to the treatment of global cataract blindness. High-quality 1-piece posterior chamber intraocular lenses are being manufactured locally for approximately $10 each. Most ophthalmologists can be trained to perform extracapsular surgery in a 1-month course. This process is particularly effective if outstanding local surgeons receive intensive training to become instructors. While the incidence and treatment of posterior capsule opacification requires further study, the development of a low-cost YAG laser may be a solution. Imaginative ways to recover costs will need to be developed if the staggering prevalence of cataract blindness is to be effectively addressed. The improved result of modern surgery may make patients more willing to pay for their operation.

Traumatic retinopathy resembling acute macular neuroretinopathy

BACKGROUND

Acute macular neuroretinopathy (AMNR) is an uncommon disease of uncertain aetiology. We report on four males who developed unilateral changes following trauma which closely resembled acute macular retinopathy.

METHODS

Retrospective review of selected cases.

RESULTS

Four male patients developed a central or paracentral scotoma immediately or soon after an accident in which they suffered moderately severe bodily injury without direct ocular trauma. Vision was reduced in three patients. All four patients had characteristic well-circumscribed, dark macular lesions best seen using red-free light. The lesions cleared slowly in the two cases who returned for review.

CONCLUSIONS

A picture that closely resembles AMNR may be seen after trauma. The mechanism may involve a sudden rise in ocular venous pressure. This may be an unrecognized cause of visual loss after non-ocular trauma which may be regarded as functional. The subtle retinal lesions may be overlooked unless the fundi are examined in red-free light and the macular dark areas are compared.

Barrier activity of fractionated human serum

PURPOSE

Breakdown of the blood-retinal barrier is a major cause of visual loss in diseases such as diabetic retinopathy, age-related macular degeneration and retinal vein occlusion.

METHODS

Human serum, fractionated by gel filtration, was screened for factors that enhance barrier activity by measuring electrical resistance across monolayers of human umbilical vein endothelial cells.

RESULTS

Two peaks of barrier-enhancing activity were detected. The larger peak was broad, contained a preponderance of albumin and increased barrier activity to 183% of controls. The barrier-enhancing properties of the larger peak, however, appeared to be associated with proteins in general and not just albumin. The fractions associated with elution of the larger peak induced maximal increase in resistance in under 1 h, relative to controls. The smaller peak was associated with molecular weights much smaller than those of proteins.

Spatial cognition in language-impaired children

Limited research evidence is available concerning the spatial abilities of children with specific language impairments. This paper reports a study of the ability of such children to use plan drawings. The participants were 23 language-impaired (LI) children (12 from special boarding schools, 11 from language units within mainstream primary schools), whose performance was compared with that of 23 non-language-impaired (NLI) children. The children were matched for age, their overall age range being between 7;0-11;11 (mean age 8;6). Tasks involved the production and utilisation of plan drawings of a model house. With one exception, results indicated that the LI children showed no deficit in ability on such tasks, and indeed out-performed their NLI peers on many of them. Implications of these findings are discussed.

Interferon-alpha 2b inhibits proliferation of human Tenon's capsule fibroblasts

To evaluate the potential of interferon-alpha 2b (IFN-alpha) as an antifibrotic treatment after glaucoma filtering surgery, we studied its ability to inhibit mitogen-induced proliferation of human Tenon's capsule fibroblasts in vitro, as shown by [3H]-thymidine incorporation. IFN-alpha inhibited fetal calf serum-induced proliferation in a dose-dependent manner in concentrations ranging from 10 to 10,000 IU/ml (P < 0.001). Inhibition was also found when IFN-alpha was added prior to the mitogen (P = 0.001); this inhibitory effect lasted at least 3 days. We suggest that IFN-alpha deserves further evaluation as a possible agent for the control of ocular fibrosis.