Determination of multi-element profiles of soil using energy dispersive X-ray fluorescence (EDXRF).

The source profile for soil in Hong Kong is important both for determination of the main air pollutant source in Hong Kong and for assessment of the impact of Asian dust storms on Hong Kong. Soil associated with different rock types have been sampled, and the concentrations of 19 chemical elements, Na, Al, Si, Ti, V, Cr, Mn, Fe, Co, K, Ca, Ni, Cu, Zn, Pb, Rb, Sr, Y and Zr, have been determined using energy dispersive X-ray fluorescence. A profile for the average soil for Hong Kong has been determined by taking average values for the different soil categories. The values for the Hong Kong soil are commensurate with values for rural soil derived by other workers, except that Hong Kong soil has much lower Fe and Ca concentrations. The abundance of Al, Ca and Fe in the average Hong Kong soil are 9.23%, 0.11% and 0.85%. We conclude that Ca provides a good marker element for identifying dust episodes in Hong Kong while Al does not.     

Measurement of K X-ray fluorescence cross-sections and yields for 5.96 keV photons.

The K(alpha), K(beta), and total K X-rays fluorescence cross-sections, as well as the average fluorescence yields for six elements with 16Z23 have been measured at 5.96 keV. The areas of the K(alpha) and K(beta) spectral peaks, as well as the net peak areas, have been determined by a fitting process. Furthermore, the I(Kbeta)/I(Kalpha) intensity ratios for these elements have been investigated. The K X-rays emitted by samples have been counted by a Si(Li) detector. Experimental values of the K X-ray fluorescence cross-sections, fluorescence yields, and the I(Kbeta)/I(Kalpha) intensity ratios have been compared with theoretical values. In most cases, there is an agreement between the experimental and theoretical values within the standard uncertainties.     

中国成年男子器官、组织中元素浓度研究

目的获得中国成年男子主要器官、组织中元素浓度代表值。方法作为系列研究第3阶段，在中国4个不同膳食类型地区，补充采集16例当地长住急死正常尸体肌肉、肋骨、肝、肾、肺、甲状腺、心、胃、脾、小肠、血液、皮肤、脂肪、睾丸、胰腺、大肠、肾上腺和胸腺共18种器官、组织样品，采用ICP-MS、ICP-AES和GF-AAS技术，测定56种元素浓度，与前两阶段相应结果合并统计取中位数作代表值。结果获得了这系列研究最多达68例中国成年男子尸体18种器官、组织样品中60种元素浓度代表值。结论除更新过去报道10种器官、组织50种元素浓度代表值外，首次获得新增8种器官、组织56种元素和已测10种器官、组织10种元素浓度代表值数据。这些结果为确定中国参考人器官、组织浓度参数参考值和在辐射防护领域其他应用提供了较前更全面和有代表性的国情依据。     

Elemental characterization of coal,fly ash,and bottom ash using an energy dispersive X-ray fluorescence technique

A total of 18 elements viz. Si, Al, Fe, Ca, Mg, K, Na, Sr, V, Zn, Mn, Cr, Cu, Pb, Ni, Co, As and Cd were analyzed in coal, fly ash and bottom ash samples collected across India using an EDXRF technique. Various indices such as element enrichment ratio, enrichment factor (with respect to crustal average) and mineral composition were calculated. Around 95% of mass was reconstructed using the concentration of elements in this study for fly and bottom ash.     

52例中国人主要器官、组织中37种元素的负荷量研究

目的估算37种元素在中国成年男子主要器官、组织和全身的负荷量。方法在我国4个不同膳食类型地区补充采集21例急死正常尸体肌肉、肋骨、肝、。肾、肺、甲状腺、心、胃、脾和小肠样品，连同过去31例尸体所采集样品对37种元素的测定浓度，按中国参考人器官、组织重量参考值估算了相应器官、组织和全身的负荷量。结果获得了我国成年男子10种器官、组织中37种元素器官、组织和全身的负荷量。结论首次获得的这些结果为确定中国人器官、组织所测元素负荷量背景值和中国参考人相应负荷量参考值及生物动力学模型参数提供较前更为系统和有代表性的依据。     

Progress in numerical modelling of the Cl influence on gamma-ray spectra from an n-gamma logging tool, by using the improved ENDF data for radiative capture.

Quality of the numerical modelling (MCNP code) of the spectrometric neutron-gamma benchmark experiment, performed at the Polish Calibration Station BGW in Zielona Gora for quantification of the main rock elements: Si, Ca, Fe and H, is considered. Elemental concentrations obtained from the measurements and simulations, for the rock models with water-filled boreholes, are in good agreement. For chlorine present in the borehole, the quality of the numerical reproducibility of the measured elemental concentrations depends on the cross section library used for the Cl(n,gamma)Cl reaction. The standard evaluated nuclear data library ENDF/B-VI Release 2 supplies imperfect data for photon production from thermal neutron capture in Cl. The improved cross sections for Cl(n,gamma)Cl are included in the ENDF/B-VI Release 8 library. Superiority of this new compilation over the previous one is shown in the paper. The accuracies for the Si, Ca and Fe determination have been improved by about 36%, 19.9% and 21.4%, respectively, when the ENDF/B-VI Release 8 library has been used for Cl.     

Trace elements in wild and orchard honeys

The present study aims the identification and quantification of trace elements in two types of honey samples: Orchard honey and Wild honey from mainland Portugal. Chemical elements content was assessed by Instrumental Neutron Activation Analysis (INAA). Concentrations were determinated for Ag, As, Br, Ca, Cl, Cs, Cu, Fe, K, La, Mg, Mn, Na, Rb, Sb, Sc, U, V and Zn. The nutritional values of both honey types were evaluated since this product contains some elements that are essential dietary nutrients for humans. Physical properties of the honey samples, such as electrical conductivy and pH, were assessed as well.     

Contamination of the coastal sea sediments by heavy metals

The distribution of major and trace elements in the coastal sea sediments along the Eastern Adriatic coast was evaluated. The concentrations of K, Ca, Ti, Cr, Mn, Fe, Ni, Cu, Zn, Ga, As, Br, Rb, Sr, Y, and Pb in 376 samples were measured on the grain fraction <2 mm by the use of energy dispersive X-ray fluorescence. Contour maps for concentrations of toxic elements Zn, Cu, As and Pb were produced in order to show metals accumulation areas.     

52例中国人主要器官、组织中37种元素的浓度

目的测定中国成年男子主要器官、组织中元素浓度。方法在我国4个不同膳食类型地区补充采集21例急死正常尸体肌肉、肋骨、肝、。肾、肺、甲状腺、心、胃、脾和小肠样品，连同过去31例尸体采集的样品，采用ENAA、INAA、ICP-AES和ICP-MS方法及必要质控措施，共测定37种元素浓度。结果获得了我国成年男子这些器官、组织样品中37种元素浓度。结论除改善I在甲状腺和33种元素在其他5种器官、组织过去报道结果代表性外，本研究首次获得我国这些元素在心、胃、脾与小肠和Be、Cl、S、I在除甲状腺中Ⅰ以外10种器官、组织浓度资料。这些结果为确定中国成年男子器官、组织元素浓度背景值和中国参考人及生物动力学模型相应参数提供较前更为系统和代表性依据。本结果还和近年文献资料及ICRP参考人新估计值进行了比较。     

Assessment of the transfer of Cs in three types of vegetables consumed in Hong Kong

A dynamic food chain model has been built for the modeling of the transfer of ¹³⁷Cs in three types of vegetables consumed in Hong Kong, namely, white flowering cabbage (Brassica chinensis), head lettuce (Lactuca sativa) and celery (Apium graveolens). Some parameters have been estimated from the experimental data obtained in this work. The experimental data include the transfer factors of ¹³⁷Cs from soil to the different vegetable species which are determined through high resolution gamma spectrometry, maximum crop biomasses for the vegetable species, the dry-to-fresh ratios for the vegetable species, the bulk density of soil layers and the average concentration of ¹³⁷Cs in air. The derived parameters include the deposition rate and the root uptake rate, information for tillage, the logistic growth model and radionuclide concentrations in vegetables. The dynamic food chain model is solved by the Birchall–James algorithm to give the ¹³⁷Cs concentration in subsurface soil, from the 0.1–25 cm soil layer, and the ¹³⁷Cs concentration in harvested and unwashed vegetables. As validation of the model and parameters, the concentrations obtained experimentally and from the model are compared and are found to be in good agreement.     

The malaria threat to the Army in Hong Kong

Changes in mosquito ecology and active anti-vector measures abolished endemic malaria transmission in Hong Kong by 1969. Unfortunately, endemic transmission of P. vivax reappeared in 1977. The threat posed to the British Army in Hong Kong however, appears to be small (5 cases since 1983), and restricted to areas close to the border with the Peoples Republic of China. Malaria biology and protective measures are discussed.     

Calcification of the stylohyoid complex in Londoners and Hong Kong Chinese

AIM: To compare the prevalence and pattern of calcification of the stylohyoid complex in Hong Kong Chinese with that in London. METHODS: The panoramic radiographs of two consecutive series of patients attending the primary dental care departments were reviewed, 862 patients in Hong Kong and 800 in London. The morphology of the stylohyoid complex was allocated to one of 12 patterns. RESULTS: A normal styloid process is significantly more prevalent in Hong Kong (P<0.01). A calcified stylohyoid ligament is significantly more common in London (15.8%) than Hong Kong (3.9%, P<0.01), whereas there is no difference in the prevalence of an elongated styloid process (7.8% in London and 8.6% in Hong Kong). Segmentation was significantly more prevalent in London (P<0.01), whereas symmetry predominated in Hong Kong (P<0.01). Although the mean age of the Hong Kong patients was significantly older than those in London (P<0.001), those with a calcified stylohyoid ligament tended only to be older (0.025>P>0.01). There was no significant difference in age for an elongated styloid process. CONCLUSION: There are significant differences in the morphology of the stylohyoid complex between London and Hong Kong. A calcified stylohyoid ligament is more prevalent in Londoners.     

Application of electrolyte analysis of pleural effusion to diagnosis of drowning

We measured concentrations of sodium (Na), chloride (Cl), calcium (Ca), and magnesium (Mg) in pleural effusion from forensic autopsy cases to examine whether they were useful for a diagnosis of drowning. We analyzed a total of 51 cases (15 seawater drowning, 10 freshwater drowning, and 26 non-drowning), and determined the following reference values. If the concentration of Na or Cl is under 65 mEq/l, a diagnosis of freshwater drowning can be made. If the concentration of Na is higher than 175 mEq/l, or that of Cl is higher than 155 mEq/l, or that of Ca is higher than 16 mg/dl, or that of Mg is higher than 15 mg/dl, a diagnosis of seawater drowning can be made. We recommend that pleural effusion from the left and the right thoracic cavities should be collected and analyzed separately because large differences may be observed between each side in the case of drowning. If one side corresponds to the reference value for seawater or freshwater drowning and the other side does not, a diagnosis of drowning can still be made according to the obtained value.     

The statistical evaluation of DNA mixtures with contributors from different ethnic groups

The effect of a structured population on the evaluation of forensic mixed stains has been considered by the authors and others. However, in countries with multiple racial or ethnic groups, it is not uncommon that contributors to a DNA mixture are of different ethnic groups. A famous example is the OJ Simpson case in which the suspect was an African-American, the victims were Caucasian Americans and the true perpetrator(s) could be from any ethnic group(s). In this paper six common mixture cases are considered and the formulae for likelihood ratios are derived. These formulae can help forensic DNA scientists acquire a better understanding of the problem. The effect of different ethnic groups is illustrated using a case in Hong Kong.     

Idiopathic osteosclerosis in the jaws of Britons and of the Hong Kong Chinese: radiology and systematic review

AIM: To compare the prevalence of idiopathic osteosclerosis in the jaws in Hong Kong and Britain. METHODS: The panoramic radiographs of consecutive patients who attended the primary care departments of the dental hospitals in Hong Kong in 1981 and 1990 and London in 1990 and of Edinburgh in 1993 were reviewed. The size of the Hong Kong lesions was measured. The literature was subjected to systematic review. RESULTS: The prevalence of idiopathic osteosclerosis in Hong Kong in 1981 and 1990, London and Edinburgh was 6.7, 5.5, 2.7 and 4.1% respectively. The prevalence of idiopathic osteosclerosis was greater in the Oriental (Chinese and Japanese) than in Western surveys. The lesions in the 1990 Hong Kong survey in the third decade were significantly smaller than those in the 1981 survey. The decrease in size in Hong Kong 1990 was also accompanied by a reduction in overall prevalence. The predilection for the mandible, especially in the premolar area, was observed in the Chinese and London series; this feature was also common to all other reports. CONCLUSION: The Chinese have a greater prevalence of idiopathic osteosclerosis than Western populations.     

Epithermal neutron activation analysis investigation of Clarion-Clipperton abyssal plane clay and polymetallic micronodules

The content of seven major (Na, Al, Cl, Mn, K, Ca, Ti, Fe) and 30 trace (Sc, V, Cr, Ni, Co, Zn, Cu, As, Sr, Rb, Zr, Mo, Sn, In, Sb, Ba, Cs, La, Ce, Nd, Eu, Sm, Tb, Dy, Yb, Hf, Ta, W, Th, U) elements determined by INAA in 13 samples of abyssal clay and two samples of micronodules collected from the North pacific Ocean Clarion-Clipperton abyssal plane is presented and discussed with respect to some rocks models.     

Population data for 12 STR loci in Hong Kong Chinese

The allele distributions at the 12 short tandem repeat (STR) loci D3S1358, HUMvWA, HUMFIBRA/FGA, HUMTHO1, HUMTPOX, HUMCSF1P0, D5S818, D13S317, D7S820, D8S1179, D21S11 and D18S51 have been determined for 284 unrelated Chinese in Hong Kong. The combined probability of identity for the 12 STR loci was about 4.1 × 10^–14 and the overall probability of excluding paternity 0.999978. None of the 12 loci were found to deviate from Hardy-Weinberg expectations according to the results of the exact test. There was also little evidence for association of alleles between loci. The results demonstrate that the loci are useful for forensic human identification and parentage testing for the Chinese population in Hong Kong. Received: 2 December 1999 / Accepted: 12 April 2000     

Mössbauer study of sediment cores from Victoria harbour, Hong Kong

The concentrations of Fe and other abundant metals in 6 m-long sediment cores from four locations in the world’s largest container port, Hong Kong, have been determined, in addition to physical characteristics and ²¹⁰Pb activities. Fe is generally present at concentrations between 2% and 3% (depending on the particle size), similar to values found in granitic rocks. Its speciation was studied by room temperature Mössbauer spectroscopy. Two Fe(II) species and one Fe(III) species were found to be present in the cores. The relative proportions of Fe(II) and Fe(III) generally changed with the depth of sediment. Most noticeably, for the core taken from near the Star Ferry Pier at the Kowloon side of Victoria harbour, the proportion of Fe(II) was fairly constant down to 4.75 m, but then decreased with depth, so that near the core base (6 m depth), the iron was present almost exclusively as Fe(III). The colour of the core changed from olive grey to olive yellow between 5 and 6 m. According to the core chronology, this depth represents ca. 1900, before the ferry pier construction, when the harbour was unpolluted.     

Gigantiform cementoma occurring in two populations, London and Hong Kong.

The gigantiform cementoma presents as multiple opacities in the tooth-bearing areas of the jaws. Sixteen cases are presented, six of British Negresses and 10 of Hong Kong Chinese females. The differential diagnosis and management are briefly reviewed.