It is even hypothesized that lead poisoning may have contributed to the decline of the Roman Empire, a hypothesis thoroughly disputed:

The great disadvantage of lead has always been that it is poisonous. This was fully recognised by the ancients, and Vitruvius specifically warns against its use. Because it was nevertheless used in profusion for carrying drinking water, the conclusion has often been drawn that the Romans must therefore have suffered from lead poisoning; sometimes conclusions are carried even further and it is inferred that this caused infertility and other unwelcome conditions, and that lead plumbing was largely responsible for the decline and fall of Rome. Two things make this otherwise attractive hypothesis impossible. First, the calcium carbonate deposit that formed so thickly inside the aqueduct channels also formed inside the pipes, effectively insulating the water from the lead, so that the two never touched. Second, because the Romans had so few taps and the water was constantly running, it was never inside the pipes for more than a few minutes, and certainly not long enough to become contaminated. However, recent research supports the idea that the lead found in the water came from the supply pipes, rather than another source of contamination. It was not unknown for locals to punch holes in the pipes to draw water off, increasing the number of people exposed to the lead. Thirty years ago, Jerome Nriagu argued in a milestone paper that Roman civilization collapsed as a result of lead poisoning.
Barrel chest generally refers to a broad, deep chest found on a patient. A barrel chested person will usually have a naturally large ribcage, very round (i.e., vertically cylindrical) torso, large lung capacity, and can potentially have great upper body strength. It can sometimes be found alongside acromegaly (an enlargement of the acra resulting from excess levels of human growth hormone (HGH) in the body). It is most commonly related to osteoarthritis as individuals age. Arthritis can stiffen the chest causing the ribs to become fixed in their most expanded position, giving the appearance of a barrel chest.Barrel chest refers to an increase in the anterior posterior diameter of the chest wall resembling the shape of a barrel, most often associated with emphysema. There are two main causes of the barrel chest phenomenon in emphysema:

Increased compliance of the lungs leads to the accumulation of air pockets inside the thoracic cavity. Increased compliance of the lungs increases the intrathoracic pressure. This increase in pressure allows the chest wall to naturally expand outward.Barrel chest occurs naturally in native people who live at altitudes of over 5500 m, e.g. the Himalayas or the Andes. These natives also have polycythemia and other accommodations for high altitude life. See also
Barrel
Pectus carinatum
Respiratory examination


== References ==