Report highlights risks to underground sewerage workers

The French ANSES undertook a campaign of individual measurements and evaluation
for sewer workers of the City of Paris, between October 2014 and March 2015.
These exploratory measurements show that they may be exposed to a cocktail of
chemical and biological agents present in the water and in the air. The
measurement campaign found exposures to carcinogens, mutagens and reproductive
toxins (CMRs), and identified tasks with higher exposures. In most situations,
the concentrations measured for each of the identified compounds, however, are
small compared to reference values ??(limit values ??for occupational exposure
= OEL or toxicological reference values ??= VTR), which does not guarantee the
absence of health effects related to particularly numerous coeexposures, the
possible synergies between pollutants, and peak concentration of certain

The health effects most commonly reported by workers exposed to wastewater are
gastrointestinal symptoms, respiratory disorders, and irritation of the nose,
throat and skin. An increase in the frequency of some infectious diseases can
also be observed, the majority of which are of limited duration and rarely
lethal. Mortality studies objectified a significant excess mortality mainly
for cancers of the liver and lung. However, it is not possible to specifically
identify one or more responsible risk factors, including chemical or
biological agents. The low status of the sewage worker profession, the lack of
collective measures and the anxiety dimension of work in sewage areas are other
factors potentially associated with increased strain.

ANSES recommends to better assess the chemical, microbiological and
psychosocial risks to make the necessary arrangements to ensure the safety and
protection of the health of long-term sewage workers and to reduce workers'
exposure by:

  • developing mandatory training for anyone who works in an underground sewerage system;

  • paying particular attention to the most exposing tasks (e.g. by mechanisation
  • implementing the hygiene and safety regulations in cooperation with the occupational health service;

  • setting up risk mapping linked to the sewage networks (identification, centralisation and updating knowledge on sewage areas with special conditions).

More info in French - Source: European Agency for Safety and Health at Work