But according to follow-up studies reported by the Nuclear Regulatory Commission (NRC), the resulting average dose of radiation that about 2 million people in the TMI area received amounted to 1 millirem, six times less than exposure to a single standard chest x-ray.
Some providers of single-country ETFs address concentration risk by using a "modified market weighting" to limit their exposure to a country's giant stocks, or simply by focusing on stocks of smaller companies.