Official website of GRiPPA - Research Group for the Prevention of Environmental Disease - edited by Giancarlo Ugazio

Gruppo di Ricerca per la Prevenzione

della Patologia Ambientale

Research Group for the Prevention of Environmental Disease

Italiano

DYNAMICS  OF  ENVIRONMENTAL  DISEASE  THROUGHOUT  MAN'S  LIFESPAN



 

CD-9

ENVIRONMENT AND HEALTH.

WATER BODIES: LITMUS PAPER OF ENVIRONMENTAL POLLUTION

 Movie2

CONTENT

01.a

RELATIONSHIPS BETWEEN MAN AND WATER BODIES

01.b

POTENTIAL ERRORS, FOR NEGLIGENCE OR MALICE, IN ASSESSING THE RISKS OF ENVIRONMENTAL POLLUTION

02.a

METHODOLOGICAL CONSIDERATIONS ON THE STUDY OF THE POLLUTION   OF A WATER BODY

02.b

DEFINITION AND COMPOSITION OF A SEDIMENT: WHY IS TOXICOLOGICAL  RESEARCH PERFORMED ON SEDIMENTS?

03

TIME EVOLUTION OF THE EFFECTS OF SINKS AND  BOTTOM SEDIMENT SOURCES FOR HARMFUL COMPOUNDS, CARRIED BY THE  WATER BODY,  WHICH REPRESENT A RISK FOR HUMAN HEALTH

04.1 NORTH ITALIAN PLAIN BASIN
04.2

FINAL  CLASSIFICATION OF RIVER SEDIMENT POLLUTION on the basis of the in vitro toxicity of organic compounds extractable with solvents and     of the concentration of heavy metals

05 PIEDMONTESE WATER BODIES: RIVERS BANNA AND TEPICE
06

 PIEDMONTESE WATER BODIES: RIVERS TORTO, CHIUSELLA AND THE MEANDERS OF VALENZA PO

07 WATER BODIES OF THE CECINA VALLEY

 

Summary

 

1.      The  water  bodies  of  the  North  Italian  Plain

  The study of the ecotoxicological conditions of water bodies is a tool used for estimating the level of environmental pollution in general. During the three-year period 1995-1997 experimental research was performed on the variations in ecotoxicological conditions of 24 of the main tributaries of the Po, with samples taken at six-monthly intervals – April and October – at 29 sites. In particular, a Piedmontese river, the Sangone was divided into six sections.

We examined both the effluent water, a precarious component of the conditions of water bodies, and the bottom sediment. Although the latter varies as a result of human activity and  natural phenomena it is a less transitory and provides a better indication of the degree of pollution. Several direct parameters of the potential risk were determined  from the samples. The content of the bottom sediment was examined for several heavy metals  considered more harmful for human health. Both the effluent water and the pore water of the bottom sediment, but above all the liposoluble organic compounds extracted from the sediment particulate, were checked for toxicity in a series of  four biological tests, consisting of living species which are highly sensitive to the harmful action of various classes of environmental poisons. This approach, albeit not absolute and which can be further developed,  provided a complete picture of the pollution in the river sediment. Examination of the bottom particulate generally confirmed expectations for rivers rising in the Apennines or the Alps and clearly indicated the level of risk of acting as pollutant sinks, with a greater risk for clay-loam sediments compared to sandy ones. Another particularly important parameter is the connection between rainfall and the concentration of risks linked to effluent water or bottom sediment. During the three-year observation period, the ecotoxicological conditions of the water bodies varied, sometimes deteriorating or, in some cases, showing considerable improvements. The research results generally confirm the expectations not only regarding the hydrogeological situations, but also and especially those regarding the sites of agricultural or industrial production plants. The absence of suitable treatment plants aggravated the situation. Clear and significant examples were the Sangone, Olona, Lambro, Mincio, Secchia and Panaro rivers. The data collected testify a serious level of sporadic pollution in the Sangone (Piedmont), whilst the other rivers showed a constant level of pollution, with the highest levels in the Lambro and the Mincio. Pollution in the latter two rivers showed no low point. Particularly worrying was the level of mercury in  the Mincio’s bottom sediment, if we remember how harmful this metal is for the nervous system in adults and foetuses, as well as causing damage to the kidneys, both in experimental animals and man. Such damage is documented by the scientific literature on mercury. From the results of the concentrations of the most harmful heavy metals, integrated with in vitro toxicity levels on series of biological tests, a ranking was drawn up for the seriousness of pollution of the various river basins, the Agogna was least polluted, whilst the worst were the Sangone, Olona, Lambro and Mincio.

 

po valley:  final classification

 

Ranking
Water body

Score

1

13 Agogna 

3.4

2

02 Pellice

6.1

3

09 Stura Demonte

6.5

4

01 Po-Villafranca

7.0

5

07 Dora Baltea

7.2

6

08 Sesia

7.3

7

14 Terdoppio

7.4

8

06 Orco

8.5

9

19 Adda

9.0

10

15 Ticino

9.6

11

05 Stura Lanzo

9.7

12

18 Trebbia

11.3

13

24 Panaro

13.3

14

21 Oglio

14.0

15

12  Scrivia

14.4

16

23 Secchia

14.9

17

04 Dora Riparia

15.1

18

20 Taro

15.6

19

11 Bormida

16.3

20

10 Tanaro

17.4

21

03 Sangone

20.8

22

16 Olona

20.9

23

17 Lambro

21.3

24

22 Mincio

21.3

 

2.      Piedmontese  water  bodies

  During 1996 and 1997, the experimental monitoring model applied to 24 tributaries of the Po, was extended to three Piedmontese hydrogeological basins of considerable environmental importance: the basin of the river Torto, the Chiusella valley and the section of Po river park at Valenza (provinces of Vercelli and Alessandria).

The findings confirm the relationship between the levels of toxicity linked to river sediments with a predominantly clay-loam composition of the sediment particulate, as well as to the concentration of lipophilic material. The first parameter could depend on the orographic conditions of the river valley, but the second is mainly due to human activity. Variations of these conditions over time may reflect the serious and prolonged drought of the first few months of 1997.

The systematic study model of the water of the Torto, with sampling – every hour for a whole day – allowed us to find the effects of human activity on pollution  through the changes in bacterial load. Maximum attention should be given to these effects, and suggest that this experimental model should be applied to water bodies which have been and still are the subject of environmental degradation, as a result of  malice or neglect.

During 2000 the ecotoxicological conditions  of two small rivers in the Turin hinterland, the Banna and the Tepice, were studied. The study of different sites along the two rivers, chosen according to both the distribution of agricultural and industrial production facilities, and residential areas – namely farms, industries and urban centres – once again showed the close connections between the components of this interactive triangle which sees man as the protagonist and target of the pollutants which he remorselessly releases into the environment to have an easier life, but perhaps not a better one or a longer one. Emblematic, despite the expectations of some researchers, is the metamorphosis of the pre-Chieri Tepice and the post-Chieri Tepice. The inhabitants of the area are living witnesses – they have to put up with a terrible stench in the hot summer months. Then, after collecting the sewage of the urban areas on one hand, and the discharge from cowsheds and pigsties on the other, these two unfortunate rivers flow towards their destination, the Po. When they reach the Po , their condition is better. In fact both the pollution of the effluent water and the negative parameters of the bottom sediment seem to improve, patchily. Perhaps this cannot be ascribed to a miraculous bio-purification. As far as the water is concerned, dilution  and capture by the sediment could be the cause of this apparent improvement, as happened with cyanide in the Danube. As far as the bottom sediment is concerned, it must be admitted that its quality depends on the distance from the polluting sewage. It should not be forgotten that a flood can carry downstream the poisons adsorbed at a particular site. The research of Cai et al., (1995) on the epidemic of Itai-Itai disease in Dayu County, China, can serve as a lesson in this regard. In fact the time-bomb can explode at any time, and after it will be no use crying wolf, it will not be a tragic fatality but tragic bloodymindedness.

 

3.      Cecina  Valley  (Tuscany)  water  bodies

  

During the years 1998/1999 the experimental model was  applied to the water bodies of the river Cecina basin. In Tuscany too, effluent water and bottom sediment samples  were taken both the river Cecina and some of its main tributaries and then studied in the laboratory.

The determination of the heavy metals present in the bottom sediment showed the presence of some of the most dangerous elements to human health, namely: aluminium, arsenic, cadmium, cobalt, chrome, iron, manganese, copper, mercury, nickel, lead and zinc. The concentration of some of these (As, Cu and Hg) present in certain sampling sites was much higher than the average concentration in the Earth’s crust: this is a clear indication of man-made environmental pollution .

 

cecina  valley

 

 

 

  The case of mercury is particularly interesting. This element which is toxic to the nervous system and the kidneys was found in high concentrations in the Botro (creek)  di Santa Maria, in the Cecina just after the convergence with the creek and in the river Possera. Our publicly presented results stimulated the public authorities responsible for environmental control to determine the mercury content not only in the effluent water but also in the bottom sediment: miraculously, by following these procedure, a high degree of mercury pollution emerged in the Cecina Valley, with values sometimes higher than those encountered by our research unit (100 ppm in the Botro di Santa Maria against 5.6 of our previous research). A year after the first meeting in Cecina, officials of the public agency confessed that the content of mercury in the water was within the legal limits, but the problems started when the sediment was considered.

Furthermore, several artificial water bodies were examined. These were located at the entrance or exit of an industrial plant. The delivery, the quantity of calcareous mineral substances dumped into the sea and the quantity of mercury present in the sediment were measured. As far as the Fosso Bianco channel is concerned, a very high concentration of mercury was found in the sediment and of calcareous substance in the water. Probably the latter was used as a sort of cover for the stratum of mercury dumped into the sea in previous decades, which can be found in the sea bed off Castiglioncello. This ploy could guarantee a certain protection from the dispersion of mercury, if it were not for the fact that the protective function could be wiped out by the first sea storm. A fact that should be pointed out regarding risk for human health is that regarding Tuscan fish-life, whether resident or seasonal. It could behave in the same way as in Minamata, Japan. By taking in mercury and concentrating it in their flesh, fish transform it into a deadly organic compound – methyl-mercury – which man can then take in by consuming the fish.

 

 

 

 

 

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