So in the show they decided to make homemade charcoal to use with their homemade smoker when they cooked the meat. They explained very accurately that using wood from a known source, allows you to make sure that there are no toxic chemicals transferred to the charcoal and subsequently the food which is cooked on it. They then proceeded to cut up kiln dried treated lumber that appeared to be scraps of wood from a construction site. Obviously, this is completely contradictory to the idea of utilizing wood but you know to be free of toxic chemicals. This is where apathy and laziness comes into play. Maybe they did not know but all commercially manufactured lumber is treated in a pressure kiln with chemicals to reduce rot and pest damage. All of the chemicals used are pesticides and are highly toxic, especially when burned.
They did correctly identify the fact that natural wood untreated emits a cocktail of toxic chemicals in the smoke as it burns. Dioxin has been identified to be one of the primary toxic gases that are created in the process of an open, uncontrolled airflow burn. These gases then permeate the food on the grill that is being cooked, or smoked. Obviously this is not a good thing and should be avoided wherever possible. The narrator accurately highlighted the fact that they will were making charcoal in order to guarantee a clean burn with as little to no toxic smoke as possible. That is a highly recommended method of cooking wherever possible. Please note that charcoal briquettes are not the same as raw charcoal. They have a number of petroleum distillates and other chemicals embedded in them to enhance the speed of the burn. They also emit toxic chemicals when they burn.
The next step showed them making the charcoal in a 55 gallon drum by elevating it off of the ground on bricks poking some holes in the bottom of the drum for airflow, lighting the fire in the drum and after allowing it to ignite all of the hardwood inside. They placed the lid loosely and slightly off center in order to reduce the flames to smoldering leaving the wood to slowly burn in a limited oxygen environment until it was entirely charcoal through and through. This is an excellent method for simply making charcoal. Unfortunately, the drum which was painted blue we will assume that it was a potable water drum. As with the new consumer food cans used for food storage those drums are coated with a plastic lining in order to reduce corrosion of the metal and reduce the possibility of a metal taste in the water. That coating commonly contains BPA. Burning BPA releases high levels of dioxin as well as toluene, and other deadly toxins. If you are going to make charcoal in a used 55 gallon drum a water drum is the best choice. But prior to making charcoal for cooking purposes you should perform an initial burn process with the lid off in order to burn off all of the coatings and toxins. The same process should be used to season and burn off any toxic residues from in an old heating oil tank or other repurposed vessel when using it as a smoker or grill. It is also why, unlike in the old days, you should not cook food directly in the can that they were packed in.
The final kicker for me that made me nearly jump out of my seat was when they boiled bear meat to render the excess fat from it prior to smoking it. This is a common process and actually highly recommended in order to assure the taste and the final outcome of the cooking process. The problem again maybe ignorance or possibly apathy whatever it was the result could have easily ended in death. 150 years ago there was a well known syndrome, which was come to be known in the early 1900s as the zinc shakes. Miners extracting zinc in mines in northern New Jersey and elsewhere around the United States were developing uncontrollable neurological issues causing them to shake uncontrollably. The cause is zinc poisoning. See the article on zinc poisoning in contaminants section. In the TV show they boiled the bear meat in a galvanized steel tub. Water or other liquids, especially high in fat or acidic content leech high levels of zinc from galvanized steel at room temperature. At high temperatures the leaching process is accelerated. I recently read of an experience where someone made beer in a similar tub. The beer had an odd metallic taste and after drinking a small amount two people ended up hospitalized with zinc poisoning.
This is a perfect example of why you need a broad knowledge of the world around you in order to survive every day. This is why a good survivalist never stops learning. Nothing that you can learn about any subject or skill will ever be worthless. It may be the smallest thing that you have learned which saves you when you see something that threatens you, and are able to avoid it. Simple mistakes like utilizing a galvanized tub to cook food or boil water could end in death.