We had our tomato plants, we had planks installed there and we had transplanted the plants. The
tomato plants were not lacking, we made our production, we also had a dog. We had finally
developed a kind of family life, autonomous community living inside the resort.
We find different kinds, big stuffing, smaller ones for the salad, cherry tomatoes, we also find a lot of
Roma, more and more sharp tomatoes. These are tomatoes for canning canned. More can be found
in the stations of big cities.
People do not have a garden. They eat canned goods. In the country, it's something else. I would not
eat, it would disgust me to know where it went. It is still not very ragoûtant, not appetizing and then
we do not know in the sewer he can pass microbes ... I could not. Yet there are two little old who
come every year to ask me if they can take seedlings.
Good sure they can. There is one who gets on his bike and he uses it. He has the choice. It's not
stuffed!
lead agents to question the evolution of society. Workers of sanitation are also interested in
consumer practices. It's things more insignificant, which, after having gone into sewers, come back to
the surface in bar screens.
Men interpret, analyze and claim knowledge "Sociological". "We know things about people's lives,
society. At the station, we have a look on it. So, a wastewater treatment technician explained, "We
see to pass vegetables, peas, carrots ... But that changed, we see all the time, with canned and frozen
foods, imports, greenhouse crops on can not keep up with the seasons. Before it was possible. When
they come back to surface after circulating in dirty waters under the city, objects can make sense, to
come back to life. Some even find their identity. An identity however problematic because marked by
their passage in sewer. This is the case of the seeds of tomatoes.
Tomato seeds are not altered by the digestive process, and their Sewerage does not take away their
germinative capacity. When the terrain and climate lend themselves, tomato plants grow in the
resorts treatment. In Montpellier, the former director of the station tells that the agents
used to grow these plants in a reserved area.
Some agents, usually older ones, retrieve plants when they have gardens. In Antibes, there are
tomato and zucchini plants "It's very pretty when everything is in bloom" (sewage treatment plant).
In Lunel in the Hérault, the guard of the treatment plant explains: "You will have to come a little
later. You will see in the spring, there is a field of tomatoes, we are invaded. "
The phenomenon is widespread and is even known to some city dwellers, friends, neighbors who
come to the stations to look for plants. These are said to be very resistant and healthy. These
qualities are attributed to the substrate in which they take root, a rich and fertile substrate.
In Lunel, the agent explains that the tomato plants are especially tall, handsome. That their stems are
particularly thick, not ordinary. In Montpellier, agents wondered about tomato species present:
Here again this agent removes from his observations a sociological reflection. The youngest people
are wondering about the recovery of these plants and the consumption of the tomatoes they
produce.
Here, there is talk of disgust, of this very present affect around the sewers and professional contacts
with wastewater (Jeanjean, 2011b). Eat or not
16
08/11/2019 Underground anamorphoses. Objects exhumed from sewers
https://journals.openedition.org/socio-anthropologie/2289#tocfrom1n4 8/10
08/11/2019 Anamorphoses souterraines. Objets exhumés des égouts
[1, 2]. Despite the fact that the air is an unfavourable environment for
microorganisms to grow, it is merely a place which temporarily occupy and
move in. The air is very often called “transport environment” because
microorganisms may be present and often can be transported over
considerable distances [1]. Microorganisms move in the air as a consequence
of wind movement, which “sweeps” them away from various habitats and
surroundings (soil, water, waste, plant surfaces, animals, and other), or are
introduced during the processes of sneezing, coughing, or sewage aeration
[2].
Wastewater treatment plant (WTP), due to its working conditions, is
considered as a major source of aerosols and may constitute an important
health risk for plant workers as well as the surrounding inhabitants [2–5].
Various bacterial and fungal communities have been isolated from all types of
aerobic and anaerobic WTPs [6]. Several studies have shown that bacteria
contained in droplets of WTPs were 10–1000 times more than that in a water
source, depending on the droplet size [3]. A number of atmospheric factors
such as temperature, wind velocity, smog, and specific humidity influence the
aerosol spread as well as the ability of microorganisms to survive in the air. At
very low humidity and high temperature, microbes face dehydration, whereas
high humidity may give cells protection against the solar radiation [3, 4, 7]. It
has also been reported that UV radiation, oxygen content, specific ions,
various pollutants, and air-associated factors are also responsible for the
decrease of the biological activity in a WTP [7, 8].
Bioaerosols may contain different types of microorganisms such as viruses,
pathogenic bacteria, and fungi, capable of causing skin, digestive system,
respiratory, and nervous system diseases and human allergies [9].
Specifically, bioaerosols emitted by WTPs can impact the air quality. In the
past, microbial concentrations in the surrounding air from the aeration tanks of
WTPs, at different heights and different distances, have been reported
[10–12].
Waste management facilities generate atmospheric emissions and liquid
effluent, which may be hazardous to human health. The potential health
hazards related to WTP aerosols are documented commonly for occupational
exposure. Effects including respiratory and digestive symptoms have been
reported in workers exposed to particulate matter and bioaerosols [9]. Similar
health problems may occur in people living near such plants who may be
exposed to this release. To guide the implementation of waste management
policies, decision-makers need information about their potential effects on
public health.
In the city of Patras, south western Greece, a municipal wastewater treatment
plant receiving domestic sewage from approximately 250,000 citizens is
located in a densely inhabited area. The WTP effluents flow to the Patraikos
gulf through a submarine pipe delivering the treated effluents in approximately
100 m from the coastline. Within a radius of 100–500 m around the WTP, 800
to 1000 inhabitants are permanently living. In order to assess the impact on
the quality of life of citizens living close to the WTP, an observational case
control study, as well as a microbiological analysis of air close to the living
areas, was performed. It is the first time that such an observational survey has
been performed in Greece. It is one of the very few studies combining
microbiological and epidemiological data in an area close to a wastewater
treatment plant.
2. Materials and Methods
The Patras’ wastewater treatment plant (WTP) has a mean inflow of
45,000 m 3 /d receiving municipal waste from 250,000 inhabitants. It is a
secondary WTP which includes indoor pretreatment with screens and coarse
bubble aerated grit clambers, outdoor primary and secondary settling tanks,
outdoor chlorination, and indoor sludge processors with belt filter presses.
2.1. Study Population
The study population was comprised of inhabitants living in the surrounding
area of the WTP (up to 500 m radius) considered as cases. A case included
any resident, living permanently for more than eight hours per day in an area
(<500 m) from the WTP. As a control was considered a resident living
permanently in an area located more than 5 km from the WTP. The
participants, cases and controls, were matched according their demographic,
socioeconomic, ethnic, and occupational background. Inclusion criteria in the
study were the permanent residency in the region, the age above 18 years,
and the agreement to complete the questionnaire. Cases travelled and stayed
abroad as well as individuals who were working far from their house for more
than 10 hours every day or who resided in the regions for less than a year
were excluded from the study (Figure 1).
Figure 1: Microbiological sampling stations and results as well as
questionnaire locations in a perimeter of a radius of 500 m.
2.2. Study Design
Study participants completed a structured self-administered validated
questionnaire distributed at their homes [13]. Participation was on a voluntary
basis. The questionnaire was divided into three parts and contained 60
questions.
The first part (23 questions) assessed baseline characteristics including
sociodemographic variables such as age, sex, family status, education,
occupation, place of work, socioeconomic status, life habits (tobacco and/or
alcohol), and general health perception. The health status was indicated by a
distinction between poor and good health. The exact wording and response
option of current health question is consistent with recommendations of the
WHO [14] and the EURO-REVES 2 group [15]. Participants were asked, “In
general how would you describe your current health status.” Those who
responded “very good” “good” or “satisfying” were considered to be in good
health, while those who responded “poor” or “bad” health were considered to
be in poor health.
The second part (10 questions) was concerned with the medical history of
participants: presence and frequency of gastrointestinal and respiratory
symptoms, joint pains, and central nervous system symptoms (including
headache, unusual tiredness, and concentration difficulties). Special questions
were related to physician diagnosed allergy, eczema, and asthma. The
grouping of symptoms was as follows: respiratory (asthma, chronic bronchitis,
and chronic sinusitis), gastrointestinal (abdominal pain and bloating, nausea,
vomiting, diarrhoea, constipation, and jaundice), skin (skin rash, ulcer on the
skin) or systemic (headache, fever, chest pain or discomfort, muscle spasms,
chills, irritability, insomnia, fatigue, weakness, and vague general discomfort or
feeling of illness), allergies at last year (drugs, powder, materials, etc.), blood
diseases (thalassemia, leukaemia), and musculoskeletal diseases
(osteoporosis, backache).
The third part (27 questions) related to health-related quality of life and overall
life satisfaction. The questions assessed the occurrence of four subjective
physical and psychological health complaints, namely, being moody, irritable,
bad tempered, and unhealthy.
The questionnaire has been piloted into 20 respondents before its use. Also, a
test-retest system was used to assess the reproducibility of the responses, 20
subjects being required to complete a second questionnaire after one-month
interval.
2.3. Air Sampling Strategy
Sampling of aerosols was performed once a week for four consecutive weeks
during summer period, from 6 sampling stations in an area of 500 m radius
around of the Patras’ WTP. The sampling points were recorded using a GPS
instrument (Magellan Explorist, Aachen, Germany). Three samplings were
performed at different times of each sampling day (morning 8.30 a.m.,
afternoon 18:00 p.m., and night 22:00 p.m.) from each sampling station, in
order to monitor the presence of microorganisms during the whole day.
Microbiological investigation was carried out during ordinary workdays when
biological treatment plant was normally working. Throughout the studied
period, during air sampling, air temperature, relative humidity, wind direction
and speed, and solar radiation were measured.
During each sampling period, an average of three readings of humidity and
temperature was recorded. The temperature (expressed in °C) and the relative
humidity (expressed in %) were measured with a portable instrument (Opus 10
Lufft, Germany).
Aerosol samples were collected using a sampler (International PBI Surface Air
System, SAS, Italy). Petri dishes (55 mm diameter) containing 25 mL of Tryptic
Soy Agar medium, (TSA Merck, Darmstadt, Germany) were placed into a
special support of the sampler. The sampling flow rate was 90 L/min. A 15 min
sampling time (volume of air > 1000 L) was used and samples were
transported to the laboratory within 2 hours for further analysis. The air
sampler was disinfected with 70% denaturized ethanol (CarloErba, Milano,
Italy) after each sampling. Petri dishes were incubated at 36°C (±1°C) for 24
hours. After the incubation period, one experienced analyst enumerated
bacterial colonies on each plate based on their cell morphology. Bacterial
colonies were differentiated on the basis of colony morphology, Gram staining,
and catalase and oxidase test. Following Gram staining, at least three
characteristic and distinctive Gram negative colonies from each plate were
identified using the API system (bioMerieux, Marcy I’Etoile, France).
Also Staphylococcus spp. (ISO 6888-2:1999), Enterococcus spp. (ISO 7899-
02:2000), and total coliforms/Escherichia coli (ISO 9308-1:2000) were
identified. The concentration of airborne bacteria was finally expressed as
colony forming units (CFU)/m 3 . No major environmental problems were
reported at the sampling stations during the survey period. Concentrations on
a limited number of days were considered representative of the annual
microbial concentrations.
2.4. Statistical Analysis
All statistical analysis was conducted with SPSS 21.0, while, for the mapping,
Arc-GIS 9.2 software was applied (ESRI, USA). Data were analysed using
descriptive statistics (Chi-test) and logistic regression to determine odds ratios
and statistical significance. Differences in selected demographic variables, as
well as smoking and health status, between the cases and the controls were
evaluated by the Chi-square test. Student’s -test was used to evaluate
continuous variables, including age and pack-years of cigarette smoking.
Unconditional multivariate logistic regression analysis was employed to
examine the association of living near the WTP and the development of health
problems by estimating odds ratio (ORs) and 95% confidence intervals (95%
CI).
The baseline characteristics were compared between the two study groups
using the Chi-square and -tests. Multivariate analyses, using a logistic
regression model, were conducted to compare the prevalence of the
investigated chronic diseases, adjusted for demographics and health-related
habits. Comparisons of the questionnaire components were performed with
Mann-Whitney test, and for multivariate analysis linear regression models
were computed. The independent variables for the models were
demographics, health-related habits, and chronic conditions.
Nonparametric statistics were usually used to test for relationships between
pathogen concentration and other factors, because total airborne bacteria
(TAB) were not normally or log-normally distributed. A nonparametric Mann-
Whitney test was used to determine whether there were significant differences
in microorganism concentrations based on the factors evaluated in this study.
Spearman’s correlation analyses were used to examine the relationship
between microorganism concentration and the other factors. A nonparametric
Kruskal-Wallis test and analysis of variance were also performed to determine
whether there were differences in microorganism concentration by sampling
location and date. A value lower than 0.05 was considered significant, for all
statistical analyses. All values are expressed as mean (SD).
3. Results
3.1. Questionnaire Validation
3.1.1. Acceptability
Ten subjects (4.2%) refused to complete the questionnaire.
3.1.2. Feasibility
Three subjects (1.3%) failed to complete the questionnaire owing to poor
eyesight.
The average time for completion was 15 minutes (range 10 to 20 minutes).
The completion rate for the questionnaire was 90% of all questions.
3.1.3. Reproducibility
In both groups (case control) the test-retest study showed that only one
answer (1.75%) was altered in one questionnaire (0.4%).
3.2. Epidemiological Survey Study
A structured questionnaire was administered to the 235 cases and 97 controls
(Table 1) to obtain information on demographics, knowledge of their general
health status, and determination of frequency of physical symptoms that they
have experienced in the study period. All respondents were asked to give
complete answers. The participants (cases and controls) self-filled in the study
questionnaire and returned it anonymously indicating only the address
(Figure 1).
Table 1: Demographic characteristics of the study population.
The 86.8% of the cases were staying at home for more than 8 hours. The
smoking habits of cases and controls were reported in Table 2. The 26.8% of
the cases considered their healthy status as nonsatisfactory (average and
bad) compared to 17.8% of the controls (). A statistically significant negative
relationship (, ) between cases living near the WTP and their general
perception about their health status was also noted.
Table 2: Comparison between cases and controls concerning smoking habits.
The incidence of allergies among the cases reached the 27.8% and most of
them were allergic to dust and pollen. Questionnaires showed that 8.7% had
iron deficiency anaemia and 27.5% were suffering from migraine headache.
7.2% had asthma and 12.9% gastritis. Dermatitis occurred in 9.3% and the
medicine use reached 41.1%. The mood as well as the perception about their
health between cases and control is shown in Table 3.
Table 3: Frequency of feelings from the inhabitants close to the WTP,
compared to the controls.
There was no increased rate of gastrointestinal disorders or myoskeletal
diseases. Similarly, there were no significant increases in the rates for
respiratory, allergic, and blood diseases. However, there was a significant
increase in the rate of neural disorders (Table 4). The frequency of the
symptoms is reported in Table 5. Almost all cases (79.6%) complained about
strong odors coming from the WTP during the evening (40.4%), during the
afternoon (20.8%), during the midday (10.7%), and during the morning
(28.1%). Odors were more intense in spring (28%) and summer (36.4%)
(Table 6). Cases emphasized problems due to the presence of the WTP as
follows: odors (50.9%), air suspensions (1.1%), and different health problems
(6.3%). It should be mentioned that 72.8% of the residents found the presence
of the WTP indispensable, but 17.4% believed that it was dangerous for their
health.
Table 4: Health symptoms associated with the distance living of WTP.
Table 5: Frequency of symptoms and medical consultation.
Table 6: Odors existence and frequency of occurrence (235 cases).
3.3. Air Microbiological Study
Forty-seven (47) measurements of temperature (°C) and humidity (%) were
carried out during the sampling period (Figure 2). The mean temperature was
13.6°C varying from 7 to 20°C and the mean relative humidity was 57.3%,
varying from 38% to 74%. During the evening sampling campaigns, the
ambient temperature ranged from 10.8 to 14.9°C and the relative humidity was
approximately 67%.
Figure 2: Measurements of humidity (a) and air temperature (b) during the
study period.
Eighty-three (83) randomly selected isolated bacterial colonies were isolated
and identified. Depending on their Gram staining, the microorganisms were
initially mainly characterized as cocci (79.5%), as Gram positive bacilli (7.2%),
and as Gram negative bacilli (13.3%). Summarized microbiological data are
shown in Table 7. Twenty-four strains (29%) were identified
as Staphylococcus aureus, 30 (36%) as Streptococcus spp., 4 (4.9%)
as Enterococcus spp., and 7 (8.5%) as Escherichia coli. Eighteen (21.7%)
strains of bacteria could not be typed. The detected loads of airborne
microorganisms at the six different sampling stations were, in general, low, but
a few higher concentrations were found at the two closest sampling stations,
(Locations number 1, number 3). Concentrations of airborne bacteria at each
sampling station are shown in Figure 3. Among the sampling locations,
Location 1 had the highest concentration of culturable airborne bacteria, with
340.89 CFU/m 3 . As the distance increased from the center of the WTP, the
concentration of culturable bacteria gradually decreased. Mean concentrations
were found lower, while the distance from the center of the WTP was
increased more than 800 m. None of the collected air samples was found
positive for Salmonella spp.
Table 7: Types of identified bacteria.
Figure 3: Average microbial count per sampling location (CFU/m 3 ).
Triplicate samples of bacteria (Streptococcus spp., Enterococcus spp.) were
collected at each sampling time. The airborne microbial concentrations
(CFU/m 3 ) corresponding to the three campaigns in all locations are
summarized in Figure 4. The average microbial load per sampling location per
day (CFU/m 3 ) is shown in Figure 5, respectively.
Figure 4: Average microbial count per sampling station (location) and sampling
period (CFU/m 3 ).
Figure 5: Average microbial count per sampling station (location) and sampling
period (CFU/m 3 ).
4. Discussion
In the present study, the impact on the quality of life of inhabitants living close
to a WTP as well as the evaluation of the air microbiological quality was
reported.
Air microbiological analyses have commonly been conducted close to sewage
treatment plants [3]. Sawyer et al. [12] measured concentrations of 126–4840
bacterial CFU/m 3 at different heights above the water surface of the aeration
tank of wastewater treatment plants. Brenner et al. [10] recorded
concentrations of 86–7143 bacterial CFU/m 3 air at a distance of 25 m from the
surface of an aeration basin well. Another study showed that the air densities
of total aerobic bacteria-containing particles, total coliforms, faecal coliforms,
faecal streptococci, total count bacteria, and coliphages increased significantly
within the perimeter of the plant during operation of the wastewater treatment
plants [11]. Other studies have shown that a percentage of the emitted
bacterial contamination can be transported over considerable distances [10].
In our study the highest microbial numbers have been reported in the locations
close to the WTP.
In order to evaluate the results of the air microbiological analyses, it should be
considered that the recorded microbial loads represent only a “picture” of the
sampling time. In connection, with the physicochemical properties of the air,
the degree of contamination at a given point can significantly change within a
few minutes [16]. An important issue of the study was the season in which the
study was performed, which is known to play a significant role in the dispersion
of aerosols and odors in the air, as well as microbes, especially during specific
seasons of the year. Complaints related to the odors were increased during
the summer months and especially during early the morning or evening, when
the percentage of humidity was higher at the sampling stations. It is suggested
that the seasonal variations of bacterial loads might be related to the
contingent meteorological conditions (humidity, temperature) and to the
intrinsic sensitiveness of different bacteria genera to these factors [17].
Some WTPs produce higher concentrations of bioaerosols compared to
others. In previous studies, using personal samplers, it was shown that
sewage treatment plant employees that have a higher incidence of headache,
tiredness, and nausea were exposed to culturable bacteria. Exposure to rod-
shaped bacteria and total number of bacteria was significantly higher in
workers reporting headache during work than in workers not reporting
headache [11].
A few studies have shown that blood tests of workers who were subjected to
aerosol inhalation indicated an increased level of antibodies against Gram
negative bacteria and intestinal viruses. The condition has been described as
“the sewage worker’s syndrome,” which has a viral origin and manifests itself
with a despondency, overall weakness, catarrh, and fever [11, 18]. Main
characteristics of the disease included general malaise, weakness, acute
rhinitis, and fever [19], accompanied by gastrointestinal symptoms. In
accordance with these studies, we recorded increased odds for the inhabitants
who lived near the WTP to develop neurological and myoskeletal symptoms at
3.37 and 1.98 times, respectively. Moreover, sewage workers and those who
live in the vicinity of a WTP have higher morbidity with intestinal and
respiratory system illnesses [11, 20]. In order to ensure public health, health of
workers, and good quality of life, it is necessary to determine the composition
and concentration of microorganisms in the air. Skin contact, ingestion, and
inhalation are the three major routes of exposure to airborne particles [20].
Microorganisms that are associated with intestinal infections such
as Salmonella spp. and enteric viruses are thought to be transmitted through
inhalation [4, 21].
Also, a nationwide survey in Sweden showed that an increased risk for
headache, concentration difficulties, unusual tiredness, and head heaviness
was reported in workers compared to the controls [18]. Similarly, in our study,
feelings like tiredness and sickness were more reported by the cases
compared to the controls. Interestingly, our study showed an increased rate in
mental disorders to the population living near the WTP. There was no
significant correlation of the WTP and the occurrence of gastrointestinal or
myoskeletal symptoms to the residents. Also, this study showed no significant
correlation concerning gastrointestinal, allergic, and respiratory symptoms
although the study sample of the controls was rather small due to the refusal
of controls (people in the city) to participate in the study.
In our study, there is a significant presence of possible pathogenic
microorganisms in the aerosols close to WTP and this concentration depended
on the distance. There is indication of the burden of microorganisms in air
according to the distance of the inhabitants. To establish aerosols impact on
the human health, more extensive studies are needed including medical
examinations in inhabitants. Such studies have not been performed to the area
of the WTP.
In order to lower the impact for public health, in areas like this, retaliatory
preventive measures should be taken by the authorities in order to protect
inhabitant’s health. Such measures could be considered the tree growing
around the WTP as well as the appropriate function of the WTP with protective
equipment for the aerosols.
Competing Interests
The authors declare that they have no competing interests.
References
1. D. C. Blanchard and L. Syzdek, “Mechanism for the water-to-air transfer and
concentration of bacteria,” Science, vol. 170, no. 3958, pp. 626–628,
1970. View at Publisher · View at Google Scholar · View at Scopus
2. H. Bauer, M. Fuerhacker, F. Zibuschka, H. Schmid, and H. Puxbaum,
“Bacteria and fungi in aerosols generated by two different types of wastewater
treatment plants,” Water Research, vol. 36, no. 16, pp. 3965–3970, 2002. View
at Publisher · View at Google Scholar · View at Scopus
3. W. Donderski, M. Walczak, and M. Pietrzak, “Microbiological contamination of
air within the city of Torun,” Polish Journal of Environmental Studies, vol. 14,
no. 2, pp. 223–230, 2005. View at Google Scholar
4. S. Karra and E. Katsivela, “Microorganisms in bioaerosol emissions from
wastewater treatment plants during summer at a Mediterranean site,” Water
Research, vol. 41, no. 6, pp. 1355–1365, 2007. View at Publisher · View at
Google Scholar · View at Scopus
5. P. Grisoli, M. Rodolfi, S. Villani et al., “Assessment of airborne microorganism
contamination in an industrial area characterized by an open composting
facility and a wastewater treatment plant,” Environmental Research, vol. 109,
no. 2, pp. 135–142, 2009. View at Publisher · View at Google Scholar · View
at Scopus
6. B. Kolwzan, W. Adamiak, K. Grabas, and A. Pawelczyk, Introduction to
Environmental Microbiology, Oficyna Wydawnicza Politechniki Wrocławskiej,
Wrocław, Poland, 2006.
7. M. Orsini, P. Laurenti, F. Boninti, D. Arzani, A. Ianni, and V. Romano-Spica, “A
molecular typing approach for evaluating bioaerosol exposure in wastewater
treatment plant workers,” Water Research, vol. 36, no. 5, pp. 1375–1378,
2002. View at Publisher · View at Google Scholar · View at Scopus
8. S. D. Pillai and S. C. Ricke, “Bioaerosols from municipal and animal wastes:
background and contemporary issues,” Canadian Journal of Microbiology, vol.
48, no. 8, pp. 681–696, 2002. View at Publisher · View at Google
Scholar · View at Scopus
9. K. Kruczalak and K. Olańczuk-Neyman, “Microorganisms in the air over
wastewater treamtment plants,” Polish Journal of Environmental Studies, vol.
13, no. 5, pp. 537–542, 2004. View at Google Scholar · View at Scopus
10. K. P. Brenner, P. V. Scarpino, and C. S. Clark, “Animal viruses,
coliphages, and bacteria in aerosols and wastewater at a spray irrigation
site,” Applied and Environmental Microbiology, vol. 54, no. 2, pp. 409–415,
1988. View at Google Scholar · View at Scopus
11. E. Melbostad, W. Eduard, A. Skogstad et al., “Exposure to bacterial
aerosols and work-related symptoms in sewage workers,” American Journal of
Industrial Medicine, vol. 25, no. 1, pp. 59–63, 1994. View at Publisher · View at
Google Scholar · View at Scopus
12. B. Sawyer, K. C. Rao, P. O'Brien, G. Elenbogen, D. R. Zenz, and C.
Lue-Hing, “Changes in bacterial aerosols with height above aeration
tanks,” Journal of Environmental Engineering, vol. 122, no. 5, pp. 368–373,
1996. View at Publisher · View at Google Scholar · View at Scopus
13. M. A. Puhan, A. Ahuja, M. L. Van Natta, L. E. Ackatz, and C. Meinert,
“Interviewer versus self-administered health-related quality of life
questionnaires-does it matter?” Health and Quality of Life Outcomes, vol. 9,
article 30, 2011. View at Publisher · View at Google Scholar · View at Scopus
14. A. de Bruin, H. S. Picavet, and A. Nossikov, “Health interview surveys.
Towards international harmonization of methods and instruments,” WHO
Regional Publications. European Series, vol. 58, pp. 1–161, 1996. View at
Google Scholar
15. J. M. Robine and C. Jagger, “Creating a coherent set of indicators to
monitor health across Europe: the Euro-REVES 2 project,” The European
Journal of Public Health, vol. 13, supplement 3, pp. 6–14, 2003. View at
Publisher · View at Google Scholar
16. R. M. Maier, I. L. Pepper, and C. P. Gerba, Environmental Microbiology,
Academic Press, San Diego, Calif, USA, 2000.
17. L. Fracchia, S. Pietronave, M. Rinaldi, and M. G. Martinotti, “The
assessment of airborne bacterial contamination in three composting plants
revealed site-related biological hazard and seasonal variations,” Journal of
Applied Microbiology, vol. 100, no. 5, pp. 973–984, 2006. View at
Publisher · View at Google Scholar · View at Scopus
18. J. Thorn, L. Beijer, and R. Rylander, “Work related symptoms among
sewage workers: a nationwide survey in Sweden,” Occupational and
Environmental Medicine, vol. 59, no. 8, pp. 562–566, 2002. View at
Publisher · View at Google Scholar · View at Scopus
19. S. Laitinen, J. Kangas, M. Kotimaa et al., “Workers' exposure to airborne
bacteria and endotoxins at industrial wastewater treatment plants,” American
Industrial Hygiene Association Journal, vol. 55, no. 11, pp. 1055–1060,
1994. View at Publisher · View at Google Scholar · View at Scopus
20. M. Lundholm and R. Rylander, “Work related symptoms among sewage
workers,” British Journal of Industrial Medicine, vol. 40, no. 3, pp. 325–329,
1983. View at Google Scholar · View at Scopus
21. C. M. Wathes, W. A. Zaidan, G. R. Pearson, M. Hinton, and N. Todd,
“Aerosol infection of calves and mice with Salmonella typhimurium,” Veterinary
Record, vol. 123, no. 23, pp. 590–594, 1988. View at Google Scholar · View at
Scopus
Een ideetje
Another idea about animal in sewers – create a service to rescue them from sewers
The idea about frog (Marijn) inspired me. Like something « save your frog » and enlarge the thing
Eco civism is required
When a animal is trapped almost of the time the fire departement is called
For me they have so many to do with others problems.
Why don’t we create a compagny which is here to catch/treat/ release / giv back to the owners all
the the animals screwed in sewers ?
must be controlled to prevent health risks or costly damage (Lund 2015).
There are many di erent biocidal products registered as rodenticides worldwide. They can be grouped together depending on their mode of application, e.g., poisoned bait, poisonous gas, contact foam, as well as speed of action, i.e., acute, subacute, and chronic (Buckle and Eason 2015). Anti- coagulant rodenticides are the most e ective and commonly used active ingredients of these biocidal products and fall into the category of slow-acting compounds. Anticoagulant rodenticides inhibit the vitamin K epoxide reductase enzyme involved in the blood coagulation process of warm-blooded vertebrates (mammals, birds) and thereby disrupt the recy- cling of vitamin K1 (phylloquinone). All anticoagulant rodenticides are either derivatives of 4-hydroxycoumarin or indane-1,3-dione and are structurally similar, but variations exist in their toxicity to target rodents. The exact mechanism of inhibition of clotting caused by hydroxycoumarin-related anticoagulation is described elsewhere (Buckle and Eason 2015; Rattner and Mastrota 2018). An e ective dose of anti- coagulant rodenticide must be ingested to have a su ciently prolonged e ect in blocking the vitamin K cycle and caus- ing failure of the blood clotting mechanism. Poisoned ani- mals die via internal hemorrhage. Active ingredients such as warfarin, coumatetralyl, and chlorophacinone that were commercialized between 1950 and 1970 are categorized as rst-generation anticoagulant rodenticides. The more potent hydroxycoumarin derivatives difenacoum, brodifacoum, bro- madiolone, and ocoumafen as well as the thiocoumarin derivative difethialone were developed and marketed in the mid-seventies and mid-eighties, respectively, to overcome warfarin resistance in rodents and are known as second- generation anticoagulant rodenticides. In recent years, ready-to-use loose, paste, and solid bait formulations are predominantly used during chemical rodent control. Bait for- mulations containing rst-generation anticoagulant rodenti- cides generally require multiple feeding of target organisms until a lethal e ect is achieved whereas second-generation anticoagulant rodenticides are more toxic and single feed- ing is often su cient for a lethal dose. The delayed action of anticoagulant rodenticides prevents the development of conditioned taste aversion or bait shyness by rodents (Buckle and Eason 2015).
As anticoagulant rodenticides act on all vertebrates, risk is high for unintentional poisoning of wildlife and domesti- cated animals. Wildlife exposure generally occurs via three pathways: through direct ingestion of rodenticide bait by nontarget species (primary exposure), by take-up of primar- ily or secondarily exposed individuals through predators or scavengers (secondary and tertiary exposure), or from consumption of terrestrial or aquatic organisms that have been exposed to anticoagulant rodenticides via emissions to the environment (secondary poisoning via environmental
emissions). Invertebrates may also be at risk from primary poisoning as a result of bait applications (Liu et al. 2015). Pathways and important aspects of wildlife exposure to anticoagulant rodenticides in the aquatic environment are illustrated in Fig. 1. Second-generation anticoagulant roden- ticides were classi ed as potentially persistent, bioaccumu- lative, and toxic substances and their release into the envi- ronment should be minimized. Despite the consideration of ‘candidates for substitution’ under European Union legisla- tion, economic relevance of anticoagulant rodenticides in the rodenticide market is still high as no chemical alternatives that are su ciently e ective but less critical are currently approved. However, recent developments gear toward their substitution with less critical active substances. In addi- tion, the implementation of a third generation to minimize ecotoxicological risks associated with the use of second- generation anticoagulant rodenticides without losing their e cacy was suggested (Damin-Pernik et al. 2016, 2017). Currently, alpha-bromadiolone is under evaluation as a new active substance within product type 14 (rodenticides) by the European Chemicals Agency. One important aspect in this development is that the economic viability of antico- agulant rodenticide use for rodent control depends not only on the cost of bait but also on the mode of application and required risk mitigation practices (Jacob and Buckle 2018). In principle, a wide range of risk mitigation measures must be deployed when anticoagulant rodenticides are used.
Environmental exposure to anticoagulant rodenticides may result during manufacture of the active substance, formulation of the biocidal product, application of baits (intended and improper use, respectively), and (inadequate) disposal of baits. Two recently published edited books attempt to gather available information on the environmen- tal risks associated with rodent control using anticoagulant rodenticides and provide comprehensive information on their chemistry and toxicology as well as their environ- mental impact on terrestrial nontarget wildlife (Buckle and Smith 2015; van den Brink et al. 2018). However, surpris- ingly little is known about the environmental fate of active ingredients after their release from baits, rodent carcasses and feces during outdoor rodent control in urban and subur- ban settings, e.g., in and around sewer systems, open space near shorelines, or around buildings and constructions. With the exception of sewers and burrows, deployment of antico- agulant rodenticide containing bait during outdoor rodent control usually happens by using tamper-resistant bait sta- tions to minimize exposure to nontarget organisms and the environment. Nevertheless, a di use release of active ingredients and respective transformation and metabolic residues from rodents and other nontarget wildlife via urine and feces may be anticipated around controlled areas. Some second-generation anticoagulant rodenticides are mainly excreted as unchanged compounds, whereas the metabolic
13
Nogmaals
Kikkers
Amfibieën sterven massaal in het riool
NIJMEGEN - Beschermde amfibieën sterven massaal een wrede dood in het rioolstelsel. Het gaat om miljoenen dieren per jaar. Gemeenten, waterbeheerders, bedrijven en natuurbeschermers komen in actie om hier een einde aan te maken.
de massale sterfte voltrekt zich grotendeels onopgemerkt in de straten van dorpen en steden. Kikkers, padden en salamanders belanden, op hun weg langs trottoirbanden, in rioolputten. Meestal is er dan geen ontkomen meer aan. Ze sterven ter plekke aan uitputting of honger.
Grote aantallen belanden via het rioolstelsel in de dodelijke filters van een rioolzuiveringsinstallatie. Dat gebeurt niet alleen in het trekseizoen, dat in maart begint, maar vrijwel het gehele jaar. Stichting Ravon (Reptielen Amfibieën Vissen Onderzoek Nederland) in Nijmegen komt na tellingen van vrijwilligers - bij drie controles in drie maanden - al tot minimaal een half miljoen volwassen amfibieën en een veelvoud daarvan aan jonge dieren.
Ook allerlei soorten muizen en zelfs vogels vinden de dood.