Parental attitudes toward ethical and social issues surrounding the expansion of newborn screening using new technologies.

AIMS: This study assessed parent knowledge of newborn screening (NBS) and parent attitudes toward NBS for untreatable conditions, NBS for late-onset disorders and informed consent in NBS. METHODS: Seventeen qualitative focus groups were held in Alaska, California, Hawaii, and Washington with mothers of children 10 years old or younger. RESULTS: Most participants did not recall receiving information about NBS, and all wanted this information prenatally. In addition, most felt that the current system of 'informed dissent' was adequate, provided they were told about NBS prior to delivery. All women supported NBS for conditions that occur in infancy without a proven treatment. However, they disagreed about NBS for disorders that manifest in late childhood or adulthood. CONCLUSIONS: The results show a general consensus among the focus group participants about issues that cause dissent among public health and health care professionals. Parent attitudes differ from those of many professional communities with regard to timing of NBS education, informed consent, NBS for disorders that lack an effective treatment, and predictive testing of children for late-onset disorders. The results highlight the need to further research parent opinions about expanded NBS using new technologies and to include parents in the development of NBS policies.

Sudden coma after subclavian catheterization.

Bilateral thalamic infarction is a very rare affection. We report here a case of bithalamic infarction during subclavian catheterization related to the accidental migration and complete occlusion of an arterial embolism to the Percheron's artery. Percheron's artery is an anatomical variation described in 1977, constituted by a solitary arterial trunk arising from one of the proximal segments of a posterior cerebral artery supplying the paramedian thalami and the rostral midbrain bilaterally. We review here the clinical presentation and discuss the aetiologies of such a cerebral infarction.

Significance of the Hygiene Charter towards different sectors in Hong Kong.

The occurrence of SARS in March 2003 has resulted in an increased interest, worldwide in emerging infectious diseases. The SARS experience provided us a lesson on the importance of promoting hygienic practices among individuals and different working sectors. In Hong Kong, a voluntary organization called the UNITE proposed a Hygiene Charter which aimed at taking hygiene to new levels. This action has been supported by individuals and different sectors including the Personal and Family, Management, Buildings, Catering, Education, Finance and Commercial, Industrial, Medical and Health, Public Transportation, Social Welfare, Sports and Culture and Tourism. As promotion and maintenance of environmental health requires input from different sectors, the signing of the Hygiene Charter provides an opportunity for individuals and the public to show their pledge and commitment to good hygiene practices. As a result, with environment improvement and good infectious disease control measures, prevention of epidemics of infectious diseases is deemed to be possible.

Predicting the 137Cs ingestion dose from marine fish consumption in Hong Kong after an accidental release.

Caesium-137 is one of the more important radionuclides released during a nuclear power plant accident. Based on a mathematical model developed earlier by the present authors for estimating 137Cs ingestion dose from consumption of marine fish in Hong Kong, doses due to an accidental release into Daya Bay from the Guangdong Nuclear Power Station are predicted. Assuming a release of 30000 TBq of 137Cs, results show that the cumulative dose rises rapidly during the first five years and then gradually levels off. In the first and 50th years after discharge, doses to an average Hong Kong citizen would cumulate to 17 and 38 microSv respectively, which are dominated by the contribution from fish cultured in Hong Kong waters. The first year dose to members of the critical group of local fish farmers is estimated to be 1600 microSv, accumulating to 3600 microSv in the 50th year. Apart from this small number of critical group members whose doses may need some monitoring, the doses to the population at large are considered small compared with an annual dose of 175 microSv from ingestion of natural radionuclides in food and drinks in Hong Kong.

Modelling the 137Cs ingestion dose from consumption of marine fish in Hong Kong.

This paper presents a compartmental model for estimating the ingestion dose, due to 137Cs, arising from the consumption of marine fish in Hong Kong. 137Cs is one of the more important radionuclides released in routine liquid effluents discharged from the Guangdong Nuclear Power Station at Daya Bay, which began commercial operation in 1994. In the model, three sea/ocean compartments are considered. Assuming the discharge of this radionuclide is maintained at a constant rate, the model shows that the concentration of 137Cs in the water and in the marine fish in the three sea compartments would become steady after 5 years. The predicted annual dose to an average local individual in Hong Kong, for a release rate of 10 GBq.y(-1), is 3.2 x 10(-5) microSv, which is dominated by the contribution from fish cultured in Hong Kong waters. The cumulative collective dose to the local population of 6 million, at 50 years of discharge, amounts to 9.0 x 10(-3) man.Sv. The annual dose to members of the critical group of local fish farmers does not exceed 3.0 x 10(-3) microSv. All these doses are small compared to the dose of around 1.2 microSv.y(-1) arising from ingestion of naturally occurring radionuclides found in marine fish. Sensitivity of model parameters and uncertainties of prediction are also studied. Difficulties encountered in model validation are discussed. Despite such difficulties. limited field data that are available show that the predicted results are generally within one order of magnitude with measurements.

Dose reduction associated with various countermeasures in freshwater fish contamination in Hong Kong.

Based on a model developed specifically for the local freshwater fish culture system, a dose transfer coefficient for 137Cs of 1.15 mSv per MBq m(-2) is obtained for the consumption of freshwater fish in the first year after deposition. Several countermeasures are suggested to reduce the ingestion dose resulting from a nuclear accident. These countermeasures include suspension of fish culture for a period of time after deposition of radionuclides, the removal of the contaminated pond water and, in the more severe cases, the removal of the sediment. The dose reductions that could be achieved by these countermeasures and the effects of their implementation times relative to the input are investigated. The time of resumption of fish culture in affected ponds and the resulting ingestion dose have also been studied in detail. It is found that reusing a pond for fresh fish culture after 6 months would reduce the ingestion dose in the following year by half as compared with that if the pond was reused a short period of time after deposition. An empirical formula linking the peak concentration in fish and the ingestion dose has been derived. The results are useful to decision-makers in limiting the ingestion dose arising from consumption of contaminated freshwater fish after nuclear accidents.

Adaptation of ECOSYS-87 to Hong Kong environmental conditions.

This paper describes the adaptation work carried out on the radioecological model ECOSYS for radionuclide transfer in the Hong Kong ecological environment. The adapted model predicts that the ingestion dose due to dry deposition in Hong Kong shows less pronounced seasonal dependence than that in Germany. This is mainly attributed to differences in climate, agricultural and farming practices adopted in the two places. Brief discussions on model sensitivity, uncertainty, and validation are also given.