It is postulated in this paper that at low doses all chemicals have hormetic/hormoligotic (beneficial) effects in living organisms. It has been known since Paracelsus that at high doses all chemicals are toxic. The combination of low and high dose effects can be empirically described by a β-curve or an inverted β-curve. A mathematical method is suggested to determine the maximum of the β-curve or the minimum of the inverted β-curve, yielding a point estimate for risk assessment.
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