Immediately following this accident, the radiation levels were high as 20,000 to 30,000 Roentgen per hour. What is considered lethal for a human being is 500 Roentgen over the course of five hours. It is believed that a human can be exposed to just two Roentgens per year without experiencing any serious problems. Following this accident, the immediate radiation levels were not known due to equipment capable of providing such high readings were inaccessible and those carrying out the tests not assuming the Dosimeter readings were correct when the readings were going off the scale. Immediate responders initially assumed a much lower radiation reading than what was actually the case and there was not adequate communication between the plant workers, first responders, and the Soviet government back in Moscow. Firefighters responding to the plant fires were among the first casualties of the radiation.
Touring the Chernobyl area is permitted by Ukraine's Ministry of Atomic Power, including access to Chernobyl's exclusion zone. The exclusion zone is controlled at checkpoints by the Ukrainian police and military under the control of Ukraine's Ministry of Extraordinary Situations, but Ukrainian tour guides are able to obtain the needed documentation (basically what equates to an "access permit") to enter the area. At these government checkpoints are also radiation equipment for checking the radiation levels as you exit the exclusion zone. There are also chemical showers on site and other precautions in the event of elevated levels of exposure to radiation. Checkpoint Dytyatky was used during my time within the secured zone. There is also government checkpoints when entering the ten kilometer zone surrounding the plant and then again when leaving/entering the town of Pripyat from its main road.
Chernobyl's exclusion zone is also known as the Zone of Alienation, The 30 Kilometer Zone, and The Chernobyl Zone. This is a 30 kilometer (19 mile) zone that surroundings the Chernobyl Nuclear Power Plant that touches the border with Belarus and also encompasses the towns of Pripyat, Chernobyl, and many smaller villages. The Chernobyl plant itself, Pripyat, and the town of Chernobyl are most frequently shown in "Chernobyl photographs" on the Internet, but not until entering the Zone of Alienation are you able to grasp the severity of this nuclear accident. There are many more homes and other buildings belonging to different villages within this 30 kilometer zone than most people realize. Some of these structures have since been buried due to high levels of radiation, but many are still standing. Only a few (older) inhabitants that refused to evacuate following the Chernobyl disaster are still living within the exclusion zone. There are, however, a number of scientists, government workers, and occasionally tourists staying within the exclusion zone at a few apartments, a hotel, and other buildings that were erected following the 1986 disaster for days at a time. Many of the older residents preferred to return home after being evacuated on the basis of preferring their hometown to living in a foreign city and not believing in an "invisible enemy" (radiation) after previously living through other major incidents as the German occupation during the war.
When touring the area there are no radiation suits or other equipment worn, but you are reliant upon the guide's experience and a Dosimeter for knowing the areas where you can walk without being exposed to high levels of nuclear material and taking other precautions like standing on a concrete surface rather than in the grass or soil where the radiation levels are more concentrated. Assuming you are following an experienced guide and apply common sense, the levels of radiation you are exposed to should not be significantly more than you will find on a commercial airplane at its cruising altitude. While there are few people that live within the Zone of Alienation, wildlife has begun to flourish within this area. Animals like wolves, boar, mice, deer, and even horses now reportedly roam the area. Besides a few cats in the town of Chernobyl that presumably belong to some of the remaining residents, I did not see any other wildlife or insects on this Chernobyl trip. Within Pripyat and Chernobyl the chirps of birds could be heard, but that was the only noise and the birds were never spotted.
The Red Forest is an area near Chernobyl (and is on the way to Pripyat) that gets its name from the pine trees that absorbed very high levels of radiation that caused them to turn a brownish-red color following the accident. The trees at the Red Forest were bulldozed and covered with soil, but a few trees remain on the ground. The levels of radiation within the Red Forest are still extremely high, which makes it still one of the most deadly places in the world; when driving through the area the Dosimeter immediately began buzzing loudly. There are reports of mutations among plants and trees now growing in the Red Forest, because of this new vegetation pulling up the radiation from the buried radioactive material, but no anomalies were personally spotted.