This paper summarizes the work done to control lead poisoning in the People's Republic of China. The work can be divided into the following four phases: (i) health surveillance of lead workers, (ii) ...health standard setting, (iii) research for early detection indicators, and (iv) improvement of the work conditions and health surveillance of "undeserved" groups. In 1949 prevention started with the initiation of the health surveillance of lead workers. Since then health surveillance has been used to supplement environmental monitoring in the early detection of lead poisoning, and the prevalence of lead poisoning has decreased. This activity has also helped to identify the needs for improvement in technological control. The next step has been the promulgation of health standards. The current standard for lead gives the maximum allowable concentration in air as 0.03 mg/m super(3) for lead fume and 0.05 mg/m super(3) for lead dust. Research on indicators for the early detection of lead has improved the quality of prevention. It has recently led to the addition of zinc protoporphyrin to the list of indicators in use. Finally the work coniditons and surveillance of workers that had earlier been considered "underserved", particularly workers in agriculture and small industries in rural areas, are being improved.
After passing toxicity and experimental therapeutic tests, four oxime cholenesterase reactivators (PAM (pyridine aldoxime methiodide), PAC (pralidoxime, pyridine aldoxime methylchloride), TMB sub(4) ...(trimedoxime), and DMO sub(4) (obidoxime, Toxogonin, LueH sub(6))) were compared in clinical trials. All of them proved capable of restoring erythrocyte cholinesterase activity and relieving symptoms and signs of organophosphate insecticide poisoning. Mildly and moderately poisoned patients can be treated by several injections of any one of these drugs alone, but severe cases need the synergistic action of atropine, as well as treatments for two to three consecutive days. Although response to treatment is stronger with TMB sub(4) and DMO sub(4), they are not recommended for routine treatment because of their dangerous adverse side effects.
Effects of allyl chloride on occupationally exposed subjects were studied in two factories manufacturing sodium allyl sulfonate. Twenty-six subjects in factory A and 27 workers in factory B were ...exposed to allyl chloride at levels of 2.6-6,650 mg/m super(3) for 2.5 months-6 years and 0.2-25.13 mg/m super(3) for 1-4.5 years, respectively. Most subjects of factory A had weakness, paresthesia, and numbness in extremities with sensory impairment in the glove-stocking distribution, as well as reduced ankle reflexes. Electroneuromyography showed neurogenic abnormalities in 10 of the 19 subjects examined, the prevalence of neuropathy therefore being 52.6%. Similar symptoms of workers in factory B were clinically much milder, and there were few abnormal neurological signs--yet electromyographic findings indicating mild neuropathy were found in 13 of the 27 subjects. No significant abnormalities of other organs were noted. Possible etiologic factors other than exposure to allyl chloride were excluded. All the evidence obtained indicates that chronic expsorue to allyl chloride mainly causes toxic polyneuropathy. The neurotoxicity of allyl chloride has also been confirmed by experimental neuropathological studies.
Adaptive Web-based learning system Alotaiby, F.T.; Chen, J.X.; Wechsler, H. ...
12th IEEE International Conference and Workshops on the Engineering of Computer-Based Systems (ECBS'05),
2005
Conference Proceeding
This paper reports a Web-based platform-independent adaptive learning system that serves both students and teachers. The content in the system is individually tailored toward student knowledge, which ...makes learning more personal, adaptive towards individual needs, and specialized. For teachers, the system provides a generic rules-based library to supervise student learning. These rules enable teachers to choose different assessment, assignment, and learning strategies. The system automatically accommodates these strategies for students according to the teacher's selections and the student's performance. Our system architecture is component-based and Web-based. The learning environment in the system is comparable to classroom learning environments.
Surveillance systems can focus on hazards, health outcomes, or both. Traditionally, public health or epidemiologic surveillance has focused primarily on health outcomes, although it also includes ...hazard surveillance.
