In antiquity it was used to manufacture cosmetics for women and make-up for the actors in Greek and Roman tragedies, and for centuries it led the field as the go-to pigment for the making of white paint. With the rise of industry in the 19th century, ceruse – or white lead, the ordinary name for lead carbonate – was manufactured on a grand scale and went into all the paint used to cover buildings, stations, bridges, ships and, later on, cars. There was white lead all over people’s houses too, where it was used to whiten the walls, and to make such things as wallpaper, oilcloth, fabrics, glazed cardboard and visiting cards.
However, this lead pigment is a poison. From 1820 onwards, it caused countless deaths among the white-lead workers who manufactured it and the house-painters who handled it. It wasn’t finally banned in Europe until 1992, more than a century and a half later.
In her book Blanc de plomb: Histoire d’un poison légal [White Lead: The History of a Legal Poison], historian Judith Rainhorn analyses why this toxic pigment was allowed to be used on such a huge scale and for such a long time, with the endorsement of public authorities.
The harmful effects of white lead were actually being described and condemned as early as the beginning of the 19th century. Inhaling the compound or allowing it to come into contact with the skin causes lead poisoning, an illness whose symptoms include dizziness, trembling, paralysis of the limbs, impaired eyesight and coma. Long-term usage (particularly occupational) can result in death.
This extremely well-researched book chronicles the journey of this industrial poison: the risks that were denied by parts of the scientific community, the concerted attempts made to hide the truth, the short-lived public outcries, the prevention campaigns, and the regulations that were promoted but never implemented.
It is a tale which has clear parallels with the much better-known story of asbestos. Just as with asbestos, public authorities were faced with a difficult choice between economic prosperity for the chemical industry and safeguarding the health of workers and the public. Many aspects of the white lead story call to mind that of the "wonder fibre": the claim that nothing could possibly replace a product whose performance was unmatched, the promotion of controlled use to stave off prohibition and, most of all, the fact that occupational hazards turned into environmental hazards. Like the asbestos so abundantly used in housing for its fireproofing and insulating properties, paints based on white lead degraded over time.
From the mid-1880s onwards, there was a renewed wave of lead poisoning cases. The victims were disadvantaged children living in slums who inhaled or ingested the dust from old layers of paint containing lead carbonate. The consequences of this second wave of exposure to white lead were outbreaks of acute encephalopathy (brain damage), psychomotor retardation and irreversible impairment of cognitive performance. The toxicology of lead and its derivatives was now well-known: they were neurotoxic substances with no threshold level, and were also toxic to reproduction.
Although the use of white lead is now banned, as is using lead to improve the octane rating of petrol, we should not forget that the use of other lead compounds in industry is still widespread. This applies, in particular, to the manufacture of motor vehicle batteries. To reduce the health hazards to the workers exposed, compulsory limit values on occupational exposure have been laid down in EU law. These limit values, defined more than 30 years ago, are patently obsolete. However, rather than banning the substances, which are seen as "vital" to the competitiveness of Europe’s automotive industry, there is talk now of scaling those values downwards.
This book is also essential reading for anyone who wants a better grasp of what is at stake in the current debate about the carcinogenicity of glyphosate, the active ingredient in the most widely used herbicide in the world, or of titanium dioxide, the pigment which has replaced white lead in all paints for industrial or home use. Reading it may help to stop history repeating itself.
Blanc de plomb: Histoire d’un poison légal by Judith Rainhorn, Presses de Sciences Po, Paris, 2019, 370 pages