With the increasingly serious problem of surface water environmental safety, it is of great significance to study the changing trend of reservoir water quality, and it is necessary to establish a water quality prediction and early warning system for the management and maintenance of water resources. Aiming at the problem of water quality prediction in reservoirs, a CA-NARX algorithm is designed, which combines the improved dynamic clustering algorithm with the idea of machine learning and the forward dynamic regression neural network. The improved dynamic clustering algorithm is used to classify the eutrophication degree of waterbodies according to the total phosphorus and total nitrogen content. Considering four meteorological factors, air temperature, water temperature, water surface evaporation, and rainfall, synthetically for each water quality condition, the total phosphorus and total nitrogen in the waterbody are forecasted by an improved forward NARX dynamic regression neural network. Based on this, the CA-NARX prediction algorithm can realize short period water quality prediction. Compared with the traditional support vector regression machine model, improved GA-BP neural network, and exponential smoothing method, the CA-NARX model has the least prediction error.
Environmental Science and Pollution Research - Zhengzhou is one of the most heavily polluted cities in China. This study collected samples of PM2.5 (atmospheric fine particulate matter with... 相似文献
Background, aim, and scope It has been known that the pollutants of electronic wastes (E-wastes) can lead to severe pollution to the environment. It
has been reported that about 50% to 80% of E-wastes from developed countries are exported to Asia and Africa. It has become
a major global environmental problem to deal with ‘E-wastes’. E-waste recycling has remained primitive in Jinghai, China.
This not only produces enormous environmental pollution but also can bring about toxic or genotoxic effects on the human body,
threatening the health of both current residents and future generations living in the local environment. The concentration
of lead in the blood of children in the E-waste polluted area in China is higher than that of the control area. But little
is known about the cytogenetic effect to human beings caused by the pollution of E-wastes. In the present study, experiments
have been performed to investigate the genetics of permanent residents of three villages with numerous E-waste disposal sites
and to analyze the harmful effects of exposure to E-wastes.
Materials and methods In total, 171 villagers (exposed group) were randomly selected from permanent residents of three villages located in Jinghai
County of Tianjin, China, where there has been massive disposal of E-wastes. Thirty villagers were selected from the neighboring
towns without E-waste disposal sites to serve as controls. Chromosomal aberrations and cytokinesis blocking micronucleus were
performed to detect the cytogenetic effect, dic + r (dicentric and ring chromosome), monomer, fragments (acentric fragments,
minute chromosomes, and acentric rings), translocation, satellite, quadriradial, total aberrations, and micronuclear rate
were scored for each subject. DNA damage was detected using comet assay; the DNA percentage in the comet tail (TDNA%), tail
moment (TM), and Olive tail moment (OTM) were recorded to describe DNA damage to lymphocytes.
Results The total chromosome aberration rates (5.50%) and micronuclear rates (16.99%) of the exposure group were significantly higher
than in the control group (P = 0.000). The percentage of DNA in the comet tail, tail moment, and Olive tail moment detected by comet assay showed that
there was a significant difference in DNA damage in the exposure group (P = 0.000). The chromosome aberration, micronucleus rate, and DNA damage observed in women were significantly higher than those
in men. Chromosome aberration and micronuclear rates of both smokers and non-smokers in the exposure group are obviously higher
than that in the control group (P = 0.000).
Discussion The use of outdated (and unsafe) ways to deal with E-wastes can lead to exposure to a variety of substances harmful to human
health. The components of pollution may enter the human body through the air, drinking water, and food chain to damage human
genetic material, resulting in genomic instability. The rates of chromosomal aberration, micronucleus formation, and the degree
of DNA damage in women in the group exposed to electronic waste were significantly higher than in men. The reason for this
may be concerned with the traditional lifestyle of the local residents or the difference of sensitivity to the exposure to
E-wastes or any others. Further investigations are needed to provide evidence to demonstrate this.
Conclusions Here, we report the obviously cytogenetic toxicity to the exposure population by the E-waste pollution for the first time.
E-waste pollution may be a potential agent of genetic mutation, and may induce cytogenetic damage within the general population
exposed to the pollution. These findings need to be considered, and steps should be taken to protect the current population
and future generations from the effects of pollution with E-wastes.
Recommendations and perspectives The above results remind us that the impact of E-waste recycling on environmental quality of Jinghai should be evaluated soon.
Moreover, it is urgent for the government to prohibit E-waste import and its processing by outdated ways. The future studies
such as pollutant details of drinking water, air, and soil in the area as well as epidemiological investigations on the harmful
effect to children must be performed eagerly. All the data available do provide a compelling case for immediate action in
both countries to address workplace health and safety and waste management.
Qiang Liu and Jia Cao contributed equally to this study and share the first authorship. 相似文献