The problem of pollution has direct consequences on human living standards, so technology should not cause harm to humans, otherwise to those who would like to use it. Therefore, environmentally friendly technology should also protect human beings by preventing pollution. Barreras et al. made a great idea in this area, “[non-environmentally friendly technologies] are responsible for the emission of a large part of the total amount of pollutants contained in the air, i.e. 40% of solid particles, 25 % of CO2,… .”(2012). They taught that environmentally unfriendly technology can produce many toxic gases that engineers should be aware of. This is because air pollution not only affects the environment, such as global warming, but also human activity and health, such as acid rain and toxic fog. Another example given by Kempton and Letendre (1996) shows that other types of pollution should also be considered in environmentally friendly technologies in order to protect human beings. “[The environmentally unfriendly technology] has the disadvantages of… environmental lead pollution during production and recycling” (1996). From this example, lead pollution during production and recycling becomes a disadvantage of environmentally unfriendly technology. Like lead pollution in this example it can cause the death of some species, including humans. From the above examples, the pollution problem causes a disadvantage for a technology, which engineers must prevent, because it is harmful to human beings. Therefore, an environmentally friendly technology should be pleasant for human being by reducing