城市供水管网健康监测与诊断:IV.监测点压力在线预测

供水管网运行状态的准确把握,对供水管网的健康监测与诊断至关重要,而监测点压力是管网运行状态最重要的标志之一。提出用于供水管网监测点压力在线预测的EMD(经验模态分解)与自回归模型相结合的方法,并对EMD组合模态所蕴含的物理意义进行了阐述。通过一实际供水管网中某监测点压力的在线预测与实际监测值的比较,验证了方法的有效性,此方法可提高城市供水管网健康的在线监测与诊断的效率。     

Heat-health warnings in regional Australia: examining public perceptions and responses

ABSTRACT

Heatwaves are an increasing environmental hazard and an important public health issue in Australia. Heat-health warnings are being adopted widely to promote protective behaviours, but there has been limited evaluation of public responses. This study used a household telephone survey to examine public attitudes and responses to heat-health warnings in regional areas in two Australian states, South Australia and Victoria. The results indicate a high level of recall of heat-health warnings and awareness about managing extreme heat. Respondents viewed heat-health warnings positively, but the effects on behaviour change were variable. Our findings suggest that the warnings may be reinforcing existing protective behaviours more than promoting change. Perceptions of heat risks were higher among women than men, but lower in older age groups. Evidence of this nature is important to identify ways to improve heat-health warnings and more effectively address the public health risks.     

Exploring the use of satellite images in the estimation of potential malaria outbreak regions

Malaria outbreaks affect nearly 40 per cent of the earth's population, most of whom live in tropical and subtropical zones. Malaria is an infectious disease that is transferred by the female mosquito of the species Anopheles. The life cycle of the malaria parasite develops in the anopheline and in the human body. These parasites require suitable environmental conditions in order to complete their development cycles within the mosquito. The relevant parameters are temperature, humidity, vegetation and water. A temperature range of 25–35°C and relative humidity range of 50–80 per cent is suitable for developing malaria outbreaks. As the fly-range of the mosquito is limited to 2–4 km, and since water pools are necessary for breeding, the vector abundance is significantly higher around water bodies. Vegetation cover also has an indirect role on malaria vector abundance. To seek to locate the regions with high potential for malaria outbreaks, we have constructed an experimental map of above-mentioned parameters via remote sensing images. A 7ETM⁺ image of Landsat platform is used in this study and maps of parameters such as land surface temperature, air temperature, air humidity, water pools and vegetated area were produced. However, a weighted combination of these layers showed some poor agreement with the distribution of positive malaria cases collected in the health centres in the region. The methodology first developed in this study is fast and accurate enough to be relied on for forecasting purposes, and could eventually lead—after further research and proper correlations—to improving the targeting of mitigation and relief operations by local health and related organizations.     

Exposure assessment for mercury from consumption of marine fish in Iran

Seven species of marine fish in the Persian Gulf and three species of marine fish in the Caspian Sea were collected from the local wholesale market in Mashhad, Iran. The mercury (Hg) concentration in muscle samples was determined by atomic absorption spectrophotometry. High total Hg concentration was found in Anchovy sprat (2.04 ± 1.23 µg g^?1) and Whitecheek shark (1.26 ± 1.85 µg g^?1) and the lowest content was detected in common carp (0.24 ± 0.24 µg g^?1) and Caspian salmon (0.25 ± 0.08 µg g^?1). The mean Hg content in all samples was 0.91 ± 1.07 µg g^?1. All samples of Persian Gulf and one sample of Caspian Sea had mean Hg concentration above 0.5 µg g^?1, the level established by joint FAO/WHO on Food Additives. Results showed that the estimated weekly intake of total Hg by a 60 kg adult is below the provisional tolerable weekly intakes recommended by joint FAO/WHO on Food Additives. For prevention of health risks, populations in Iran need to consume fish in moderate amounts.     

Trace metal contents in some brands of canned beef in Nigeria

The concentrations of cadmium, chromium, copper, lead, zinc, manganese, iron, cobalt, and nickel in some brands of canned beef in Nigerian markets were determined by atomic absorption spectrophotometry. The mean concentration ranges for these metals in mg?kg^?1 were 0.02–0.37 for Cd, <0.04–0.75 for Cr, 1.1–2.4 for Cu, <0.001–1.5 for Pb, 1.1–8.0 for Zn, <0.04–0.57 for Mn, 13.8–28.8 for Fe, 0.05–0.26 for Co, and 0.8–5.9 for Ni. The estimated dietary intake of metals from these products did not indicate any risk since the values were far below the permissible dietary intakes.     

Assessing environmental exposure and health impacts of gold mining in Ghana

Understanding the extent to which people are being exposed to environmental contaminants helps to identify those populations which may be disproportionately exposed to the contaminants of potential public health concern. This study represents the first report of a comparison of heavy metal arsenic (As), mercury (Hg), cadmium (Cd), cobalt (Co), copper (Cu), lead (Pb), platinum (Pt), zinc (Zn), and manganese (Mn) concentrations in the blood of residents of mining and non-mining communities in Ghana. Blood sampling, health records, and interviews were used in this study to establish the links between the levels of contaminants and health effects in humans within a mining and non-mining community in Ghana. Results of this study show that mean concentration of As in blood in Tarkwa Nsuaem Municipality/Prestea-Huni Valley District (TNMA/PHVD) (mining communities) and Cape Coast Metropolis (CCMA) (non-mining community) was 18- and 2-fold higher, respectively, than the WHO guideline value of 0.002?mg?L^?1. The mean concentrations of As, Cd, Pb, Hg, and Mn were elevated up to 20-fold higher in the blood of resident adults and children in TNMA/PHVD than in CCMA. The risk of acute respiratory infections in the exposed populations of TNMA and PHVD were approximately 41- and 12-fold greater than the unexposed group. The risk of diabetes mellitus in the exposed populations of TNMA and PHVD were also approximately 20- and 4-fold higher than the unexposed group. In TNMA and PHVD, 40 blood donors were suffering from hyperkeratosis or pigmentation unlike their CCMA counterparts. Data suggest a potential association between mining activities and the levels of these heavy metals. However, the proportion of anthropogenic contribution to the levels of these metals in the blood remains uncertain. This uncertainty seems to be the umbrella under which both government and mining companies continue to hide, leading to inaction.     

Field dissipation and health hazard assessment of Fenhexamid on Egyptian grapes

Dissipation behavior and hazard assessment of the fungicide fenhexamid applied to grapes were investigated under climatic conditions in Egypt. Fenhexamid residues were extracted from grape samples with ethyl acetate. The extract was cleaned up by QuEChERS (quick, easy, cheap, effective, rugged, and safe) method, and determined by gas chromatographic method (GC-μECD). The average recoveries ranged between 94.2% and 99.4% with associated relative standard deviation not exceeding 12%. The estimated limit of quantification for fenhexamid was 0.1 mg/kg. The field results showed that fenhexamid dissipated rapidly from grapes and had a half-life of approximately 4.21 days. Hazard assessment was evaluated by using the hazard quotient (HQ). Data showed that the HQ value was significantly less than HQ = 1. Results indicate that hazard of fenhexamid use in grape even at 1.5-fold higher than recommended dosage was negligible to humans. This study could provide guidance for safe and reasonable use of fenhexamid in grapes and prevent health problems to consumers. However, further hazard assessment studies are needed to ascertain the hazard of fenhexamid residues on grape to vulnerable groups, including children, pregnant women, and elderly consumers.     

东莞市蔬菜基地蔬菜中喹诺酮类抗生素污染特征及健康风险

利用超高效液相色谱-串联质谱(UPLC-MS/MS)技术分析了东莞市蔬菜基地蔬菜中4种喹诺酮类抗生素的污染特征,并对其健康风险进行评价.结果表明,东莞市蔬菜中普遍检出喹诺酮类抗生素,以诺氟沙星和环丙沙星为主,其次是恩诺沙星,检出率均在80%以上,最高含量均大于100μg/kg(干重),平均含量近20μg/kg;不同基地和不同类型的蔬菜中喹诺酮类抗生素的含量与组成特征差异较大,总含量为叶菜类(49.87μg/kg)>根茎类(44.81μg/kg)>瓜果类(11.21μg/kg);通过食用东莞市蔬菜摄入喹诺酮类抗生素的量低于日允许摄入量,健康风险较小.     

Agricultural chemical exposure in small farmers in Guyana

A study of self-reported injury from agricultural chemical exposure was conducted in farmers in rural Guyana. One hundred and ninety agricultural workers were studied, of which 167 (88%) were male. Morbidity from agricultural chemical exposure was common, with 87 farmers (46%) reporting having experienced at least one episode of illness after agricultural chemical exposure. Relatively few of the farmers sought medical assistance for their symptoms, with only 20 farmers (11%) visiting a local doctor and only two farmers (1%) reporting going to a hospital for treatment. Local farmer use of protective equipment was limited. Pyrethroids and herbicides paraquat and glyphosate were the most commonly used agricultural chemicals in the population studied. Data showed that exposure to agricultural chemicals remains frequent, with incidence of severe injury requiring less frequent medical attention.     

Tissue distribution of antimony (Sb) in piglets orally given graded levels of Sb (V)

The potential risks from oral intake of soil antimony (Sb) depends mainly on the amount of metal ingested and its bioavailability. Relative bioavailability may be determined by comparing Sb present in soil to a reference compound, taking into account accumulation in different target tissues or excretion. However, due to the lack of scientific knowledge concerning the fate of Sb in the organism, there is a need to study the absorption and distribution of Sb in order to select target tissues for assessment of bioavailability of Sb in soils. Thus, 45 piglets were exposed to a soluble pentavalent antimony salt (KSb(OH)₆), for 15 days at concentrations ranging from 0–1600 µg Sb/kg body weight (BW) per day. Following the exposure period, blood, plasma, liver, spleen, kidneys, hair, bone, bile and urine were obtained to measure Sb concentrations by ICP-MS. Results showed that tissue Sb levels were dose-related. Higher Sb concentrations were found in urine, kidneys, hair, bone and liver. Sb(V) was not detectable in blood and plasma. In the case of highly contaminated soil with soluble forms of Sb in concentrations ranging from 200–1600 µg Sb/kg BW, kidneys, liver and spleen are the most reliable compartments to determine Sb bioavailability from soil. However, for the soils with lower levels of contamination and a low Sb bioaccessibility, urine may serve as a relevant compartment.