The standard progression of the effects of the roulette of environmental pollution on human health may be accelerated due to toxicological synergism, based on the co-presence of various environmental poisons. This may be compared to watching an action film with a projector that had been set to speed up the images.

For example, this undesirable biological effect may be caused by the fact that more than one poison affecting on the nervous system, or several poisons effecting the kidneys attack at the same time both the central nervous system and the kidneys. In the case of exposure to a single poison: mercury or lead, tin or aluminium, the harm could be limited to certain level. However, should they all act together the lesions caused would be more serious than a mere arithmetic addition, both from the point of view of the gravity of the illness and above all for the speed with which the clinical horizon would be reached. A similar aspect can also affect the kidney should it be attacked by a combination of lead and mercury. Then the same risk of toxicological synergism occurs when the bone tissue is affected by lead together with adequate doses of cadmium. The former metal is the cause of osteoporosis, whilst the latter brings on rickets. The timing and the gravity of the symptoms is considerably anticipated by this inauspicious coupling, which is not rare or impossible. The consequence is the possible early occurrence of disease-induced fractures, i.e. those which occur spontaneously under the body's weight, without accidents.

The combined effect of environmental poisons, which could also be called the cocktail effect, occurs because the balance between  attack and defence of the tissues is shifted in favour of the former. Hence, all the pathological phenomena which arise once the clinical horizon has been crossed, and in particular irreversibility of damage, occur earlier than expected. These include an impoverishment of the standard of living as well a lower life expectancy, as mentioned in CD-4.

It is understood that, above all in the case of toxicological synergism, the physician must be aware of the risks of environmental pollution which affect human health and must try to build an honest case history which can lead to a correct diagnosis. Above all it is desirable that there is the awareness that can provide true primary prevention.