Fans are desperate to lay their hands on the larger-screen iPhone 6, thanks to Apple's "hunger marketing". Analysts are busy debating which of the phones giants --Apple, Samsung or Xiaomi -- leads the Chinese market. But too few people spare a thought to environmental damage caused by cell phones. Indeed, smartphones are great innovative tools, but they also make people change phones that are as good as new, and thus worsen the already serious environmental pollution. Theoretically, a cell phone can be used for eight years, but in practice one lasts 15 months on average in China, according to D. Phone. From production to disposal, cell phones, even those made by big brands like Apple and Samsung, pollute the environment. A study by the Ecology Center of Ann Arbor, Michigan, and ifixit.com showed that each of the 36 dissected phone models contained at least one of the following poisonous elements: lead, bromine, chlorine, mercury and cadmium. And these poisonous elements are linked to birth defects, impaired learning and other serious health problems. China, the largest phone-making country and smartphone market, should be alarmed by the environment damage caused by cell phones. So there is no reason to celebrate the "good news" that last year China produced about 1.46 billion cell phones, about 81.1 percent of the total global output, and 340 million smartphones were sold in the country -- a figure that is expected to cross 400 million this year. In fact, Apple's production chain best shows the urgency for China's manufacturing sector to climb up the global value chain. Apple products are designed in the US, assembled in China and sold across the world. And while Apple takes away the lion's share of the profits, Chinese workers can barely manage to keep their pots boiling and the environment ends up paying the heaviest price. The purpose of the writer writing the passage is to   _  .
criticize the young people for changing their cell phones too fast call on us to care about our environment when using cell phones tell us the dangerous effects of using cell phones criticize the foreign companies making cell phones