The amount of lead in the blood and tissues, as well as the time course of exposure, determine toxicity. Lead poisoning may be acute (from intense exposure of short duration) or chronic (from repeat low-level exposure over a prolonged period), but the latter is much more common.
The COO is responsible for the daily operation of the company, and routinely reports to the highest ranking executive, usually the chief executive officer (CEO). The COO is usually the second in command at the firm, especially if the highest ranking executive is the Chairman and CEO.
The chief operating officer is the second-in-command and often succeeds to the top position when the CEO steps down. His duties often overlap with that of the CEO but his primary responsibility is to manage day-to-day operations by meeting with individual department heads. Depending on the size of his facilities, he may walk company floors daily to observe operations and the progress of projects first-hand.