I’m constantly surprised (and annoyed) by the shear number of Contaminated Land Risk Assessment reports that include phrases such as “there is no risk from groundwater at the site” or “the reported benzene concentrations pose no risk to human health”. Such reports can be written by huge multinational consultancies or sole traders, recent graduates or experienced practitioners – it seems a universal conceit.
It’s the “no risk” part that makes me wince. I really doubt it’s true for the vast majority of times it is used.
To the author of “the reported benzene concentrations pose no risk to human health”, I would counter that there is always some risk to human health from benzene, no matter how small the concentrations or the perhaps convoluted exposure pathway it would have to take to reach a human. At best, anybody reading the report will infer the likely meaning from the statement that benzene concentrations are not really a concern to human health at the site and have no issues with that. At worst (and acknowledging that I’m not a lawyer), someone with a litigious streak could argue that the statement is misleading or untrue as there will always be some (perhaps infinitesimal) risk – leading to a non-payment of fees or other consequence, why risk your PI insurance or premiums?
To reach their conclusion, the author had probably compared the reported concentration to some kind of assessment criteria. These are often risk based and derived based on minimal risk thresholds. Having reported concentrations below such a threshold does not equate to “no risk”, but more likely “acceptable risks” or “not potentially significant risk”. Of course, some assessment criteria are based on parameters such as odour, tainting or detection limits – being below (or above!) such criteria would have no bearing on “risk”.
So why the picture of a meteor approaching Earth you ask? It’s my goto scenario for explaining my thinking regarding “no risk”…
Meteorites are space objects, such as an asteroid or comet, which crash into the Earth’s surface. I also use the Earth’s surface when I’m walking my dog or driving my car. Whilst most people would accept there is “no risk” of being hit by a meteorite, it’s not strictly true – there must always be some chance I could be hit by one! So I submit a pedantic “there is an acceptable risk of being hit by a meteorite” instead.
(Don’t get me started on Lottery tickets – I doubt they’d sell many if they advertised them as “no risk of winning the jackpot”!)