Excessive sun exposure is a common cause of brown spots on the scalp due to conditions such as melasma and actinic keratosis, per the Mayo Clinic and the American Academy of Dermatology. While these conditions differ slightly from each other, they both are frequently caused by excessive ultraviolet radiation. Continue Reading.
Mexico is a part of North America. Maybe you are thinking of Northern America, which is a tricky area as sometimes Mexico is included and sometimes it is not. Northern America â¦ is the northern portion of North America, in which Canada and the United States are usually the two sole members.
Mexico is part of the UN, OECD, G-20, G-5 , also Mexico is the country with most free trade agreements, being the NAFTA and the Alianza del Pacifico the most important. Now I think you know what's Mexico in geography, economics, biology and society.