英语作文,关于Packing(包装)的利弊
发布网友
发布时间：2022-05-27 12:25
共2个回答
热心网友
时间：2023-10-22 10:33
1、回收利用废弃塑料时，分类十分困难，而且经济上不合算。
2、塑料容易燃烧，燃烧时产生有毒气体。
3、塑料是由石油炼制的产品制成的，石油资源是有限的。
【塑料引起的危害】
早在60年代中期，人们就发现聚氯乙烯塑料中残存的氯乙烯单体，能引起使前指骨溶化称为“肢端骨溶解症”的怪病。从事聚氯乙烯树脂制造的工人又常会出现手指麻木、刺痛等所谓白蜡症（雷诺氏综合症）。当人们接触氯乙烯单体后就会发生手指、手腕、颜面浮肿、皮肤变厚、变僵、失去弹性和不能用力握物的皮肤硬化症，同时还有人口现脾肿大、胃及食道静脉瘤、肝损伤，门静脉压亢进等症。70年代后又在一些聚氯乙烯生产厂中，发现有人患有一种极少见的肝癌—肝脏血管肉瘤。此后业昔虽然尽量控制聚氯乙烯树脂中单体含量，但并未彻底解决，故在1975年美国首先提出禁止用聚氯乙烯塑料包装食品和饮料。
由于塑料制品在动物体内无法被消化和分解，以致误食后即能引起胃部不适、行动异常、生育繁殖能力下降，甚至死亡。如我国的某些动物园就发生过动物误食游人丢弃的塑料食品袋致死的不幸事件。
1970年到1987年间，人们调查了太平洋海域的543头白额鹱等大型海鸟，由于它们分不清塑料与海草，竟在其中458头胃中找到了塑料类物品，海龟的胃中也有。
农田里的废农膜、塑料袋等同样会引起牲口误食因厌食而死亡。此外，当它们长期残留在农田中后，既会影响土壤透气性，阻碍水分流动和作物根系发育，还会缠绕农机，影响田间作业，长此下去又能影响深层土壤，使土壤环境恶化，进而威胁人类生存。
废弃塑料对海洋的污染已经成为国际性问题。海洋漂浮物中泡沫聚苯乙烯占22％，其它塑料占23％。这些废弃塑料不但会缠住船只的螺旋桨，损坏船身和机器引起事故和停驶，给航运造成重大损失，而每清除1吨海上垃圾要用去清除陆地垃圾10倍的花费。1995年香港为打捞4765.6吨海上垃圾，耗资1200万港元。
热固性塑料同样会严重污染环境。例如由玻璃纤维增强塑料（FRP）制成的中、小型船身，当它们一旦报废就很难处理。在日本每年约有3000只这类废船被丢弃在港岸，既影响观瞻，又影响渔业，成为日本沿海的一大公害。
塑料焚烧时会产生有毒气体二恶英,它包括210种化合物。它的毒性十分大，是氰化物的130倍、砒霜的900倍，有“世纪之
Plastic disadvantage
1, recycling of plastic waste, the classification is very difficult, but the economy viable.
2, plastic easy combustion, proce toxic gases when burned.
3, plastic is a proct made from petroleum refining, and oil resources are limited.
【】 Harm caused by plastic
As early as the mid-60s, it was found in PVC resial vinyl chloride monomer, can cause melting of the former phalangeal known as "acral osteolysis syndrome" of the disease. Engaged in manufacturing PVC resin workers often appear finger numbness, tingling in the so-called Ericerus disease (Raynaud's syndrome). When people contact with vinyl chloride monomer will happen after the fingers, wrist, facial swelling, skin thickening, variable stiff and lose flexibility and grip strength should not matter the skin sclerosis, as well as the population is splenomegaly, stomach and esophageal varices tumor, liver injury, portal pressure等症hyperfunction. 70s and then in a number of polyvinyl chloride proction plant, we found it was suffering from a rare liver cancer - liver angiosarcoma. Since then the instry as far as possible control celecoxib Although PVC resin in the monomer content, but not completely resolved, it is in the United States first proposed in 1975 prohibiting the use of PVC packaging food and beverages.
Because of plastic procts in animals can not be digested and broken down so that after the incorrect use can cause stomach discomfort, abnormal operations, fertility decline in reproctive capacity, or even death. Some of our country such as the zoo animals on the incorrect use of visitors had discarded plastic food bag to death the unfortunate incident.
1970 to 1987, the people of the Pacific Ocean investigate the amount of 543 white large seabird Procellariiformes, because they are hard plastic and seaweed, in which 458 has the stomach to find plastic items, turtles also have the stomach.
Fields of waste plastic sheeting, plastic bags, such as the incorrect use of the same will cause livestock deaths e to anorexia. In addition, when their long-term resie in the farmland, the soil will affect permeability and impede water flow and crop root development, but also winding machinery, the impact of field operations, the long run can affect the deep soil, the soil degradation of the environment, thereby threat to human survival.
Discarded plastic on marine pollution has become an international problem. Marine floating polystyrene foam materials 22%, 23% other plastics. These discarded plastics will not only haunt the vessel propeller, hull and machinery damage caused by the accident and stopped, causing significant losses to shipping, and each removal of 1 ton of garbage in the sea should go clear the land 10 times the cost of trash. Hong Kong in 1995 for salvage 4765.6 tons of garbage in the sea, costing 12 million Hong Kong dollar.
Thermosetting plastics will seriously pollute the environment. For example, glass fiber reinforced plastic (FRP) made of small and medium-sized hull, when once they scrapped it is hard to deal with. In Japan each year about 3000 of such abandoned hulk shore in Hong Kong not only affects the visual impact and the impact of fisheries, coastal areas in Japan a major public hazard.
Burning plastic will release poisonous gas dioxin, which includes 210 kinds of compounds. Its toxicity is very large, are 130 times more cyanide, arsenic 900 times, the "century
热心网友
时间：2023-10-22 10:33
还是自己写的好。。
