Usually, I suspect, most people associate new technology with decreasing pollution; that is not necessarily the case.  Old technology–thousands of years technology, such as the rake, creates no air pollution, unlike gasoline powered leaf blowers.  The rake is also quiet, making little or no noise beyond a soothing susurration as the leaves brush against each other and the grass.  The leaf blower, of course, roars like a horrible hive of very angry bees–virtually stinging the ears and obliterating all hope of contemplation or concentration.  In little more time (if more at all) it took two men to push leaves across a neighbor’s lawn today, they easily could have pulled the leaves into a pile with wide-swath rakes.