So-called chimney-sweep cancer was a particularly common condition in 18th century Europe. Traditionally, chimney sweeps hired young boys, generally orphans or children from poor families, who were small and could climb inside the chimney to brush it. Although chimney sweeping was common across Europe and North America during the 18th century, chimney-sweep cancer was predominantly found in English chimney sweeps, probably because the chimney flues were narrower and Londoners often hired young boys aged between 4 and 7 years who could fit through the ducts. Additionally, the poor hygiene conditions at the time meant that these children would bathe normally once a year and would often work naked, repeatedly exposing their skin to toxins in the chimney soot. In England at that time there was no law regulating child labour and the first Chimney Sweepers Act was passed in 1788, stating a minimum working age of 8 years. The British Parliament, concerned about child labour exploitation in this setting, passed a law in 1834 prohibiting children younger than 10 years to work, and children younger than 14 years to be engaged in cleaning chimneys. In 1840, the law changed and the minimum age of apprenticeship for chimney sweeps was 16 years. However, as with previous legislation, these age thresholds were largely ignored because of the lack of enforcement and children under the age of ten were still hired to clean chimneys. In France, worried by social injustice, the novelist and human rights activist Victor Hugo (1829–83) denounced the exploitation and slavery of children in 1862, through the character of Cosette in his novel Les Misérables. In his novels, Hugo tried to raise public awareness of the lack of enforcement of laws passed in countries in the middle of the industrial revolution.