Sperm counts have been decreasing in men in Western countries for over 100 years, due to environmental pollutants and consumption of foods high in plant oestrogens. The Israeli study showed that exposure to electromagnetic radiation emitted from cell phones decreases sperm counts in at least 50% of men. Reduced fertility was greatest in men who carried their phones in pockets close to their groin. This was a small study involving only 106 men, so more research is needed to determine the extent of the problem.