1 A highly toxic form (methylmercury) builds up in fish, shellfish and animals that eat fish. 2  Fish and shellfish are the main sources of methylmercury exposure to humans.3  Mercury exposure at high levels can harm the brain, heart, kidneys, lungs, and immune system. A highly toxic form (methylmercury) builds up in fish, shellfish and animals that eat fish. 2  Fish and shellfish are the main sources of methylmercury exposure to humans.
The 2016 Boston Marathon will begin on Monday, April 18. Here is some of the basic information you should know about the historic event. Length: According to Olympic standards, marathons are 26 miles and 385 yards, or roughly 26.2 miles long. Route: The Boston Marathon starts on Main Street in Hopkinton, Mass.
5k race = 3.1 miles. Most beginner runners will take an average time to finish a 5k race of 30 - 40 minutes. 10k race = 6.2 miles. The typical time it takes to do a 10k race is 1 - 1 1/2 hours. Half marathon = 13.1 miles, 21.7 kilometres. A respectable time it takes to do a half marathon is 2 - 2 1/2 hours. Marathon = 26.2 miles, 41.2 kilometres. The average time it takes runners to do a marathon is between 4 - 5 hours. 5k runs have turned in to being a very popular way for charities to increase both funds and awareness of their particular causes.