Now, using the Vinogradov lab's method, the team made the first direct measurement of
fine oxygen concentration gradients in live bone marrow.
But pollution also covers hundreds of chemicals which are
fine or even beneficial at low levels but which if released in large quantities or in problematic circumstances cause «harm» — like phosphorus (grows your veges but also leads to toxic cyanobacterial blooms which kill cattle), nitrogen (grows crops kills many native species of plants and promotes weed growth costing farmers), copper (used as an
oxygen carrier by gastropods but in high
concentrations kills the life in sediments which feed fish), hormones like oestrogen (essential for regulating bodies but in high
concentrations confuse reproductive cycles especially with marine life) or maybe molasses from a sugar mill (good for rum but when dumped into east coast estuaries used to cause
oxygen sag in estuaries leading to massive fish kills).