the most dangerous career field
Acute Toxicity of Organic
compounds in sludges
HEALTH effects associated with wastewater treatment,
disposal, and reuse. C.S. Clark. Published in WEF's Journal
Water Pollution Federation (1987) vol 59(6): pp 436-440

Hadeed reported that the wastewater industy has retained its
number one status as the most dangerous career field based on
the results of the 1986 Annual WPCF Safety Survey.

In New york, 164 workers from 14 wastewater plants work had a
higher frequency of uninary mutagens, after controlling for
smoking, than 72 water treatment workers in the same
municipalities. The authors stated that while these findings
provided strong evidence of increased exposure to mutagenic
substances among wastewater workers, the long-term health
effects of their exposure was unknown.

In a review of the literature on on the biological health
risks associated with wastewater and sludge handling and land
application, Block concluded that the literature on the
health effects of exposure to wastewater sludge on the health
of workers was scarce.

A review of serologic methods to determine infections from
exposure to wastewater and refuse concluded that four of the
five wastewater worker studies reviewed there was evidence
that exposure wastewater/sludge carried with it a slight risk
of viral infection, usually limited to those with the highest

Jakubowshi reviewed 11 U.S. Environmental Protection Agency-
sponsered studies of the potential health effects associated
with the treatment and disposal of wastewater and wastewater
sludge. He concluded that although most of the evidence was
negative, the problems in quantifyinig exposure and the
absense of a clear endpoint for necessary effect must be

Fifteen outbreaks of cysticercosis in cattle related to
wastewater and sludge application on farmland in Denmark were
described and likely infection sources identified. Results of
two serologic surveys of Scottist cattle for ELISA antibodies
for taeniid parsites were presented by Sewell et al. and the
need for more specific diagnostic procedures to make testing
more usful was expressed.

Havelaar and Jones discussed various aspects of the
potentuial for salmonellosis resulting from agricultural use
of waste materials. Angus discussed several factors which
could reduce possible infections Cryptosporidium from the
land application of agricultural and domestic sludges.

In a discussion of epidemiological studies of wastewater
populations, the need for a health status survey of the
exposed population was stressed. A review of the infectious
risk ofsarcosporidia from irrigation was sludge revealed that
the risk was increased by the high resistence of Sarcocystis
spp. cysts to environmental conditions.

The potential role of wastewater and sludge in spreading
ascariasis in Europe, the efficiency of various treatment
techniques, and the need for surveillance programs was
reviewed by Pawlowski and Schultzberg. Watson reviewed the
potential health risk to humans and animals from bacteria,
helminths and viruses in sludges applied to land. Wekerle
presented a review of sludge as a vecter for transmission and
identified several research needs.

In a report on the domestic waste exclusion of hazardous
waste discharged to POTWs numerous case studies were referred
to which involved sewer maintenance workers who have been
injured or killed from hazardous gases formed in sewers.
Pollutant incident reports from 10 POTWs reflect occurences
of occupational health hazards were cited.

Melius cited some difficulties in designing medical
surveillance programs for hazardous waste workers because of
usual exposure to low levels of multiple contaminants and the
occasional exposure to potentially high levels
Bacteria- and
aerosols at sludge
wastewater treatment
"Respiratory Hazards of
Organic Dust Exposure
Organic compounds -
toxic impact on the
central nervous system