While the overall impact of recycling is a positive one, the toxic byproducts of the recycling industry are considerable. Given the propensity of landfills to contribute to highly dangerous leachates that can contaminate groundwater supplies, a proportion of these materials are known to eventually make it into surface water supplies, as well.
Fish and other freshwater organisms are highly susceptible to pollution. One of the most profound effects of recycling wastes that contribute to declining fish stocks are the powerful endocrine disruptors that alter the ability of these creatures to reproduce properly. With nearly 40% of freshwater fish in North America in decline, according to a 2008 study, this is a significant impact.
However, the impact of business as usual is far higher. Recycling has been shown to decrease the amount of nutrients that contribute to dead zones and low-oxygen conditions. The recycling of metals also helps considerably, but reducing the amount of toxic materials that are discharged into rivers and streams as a result of mining operations.
