ENVIRONMENTAL COMPANY OF SAO PAULO STATE – CETESB

REGIONAL CENTRE OF STOCKHOLM CONVENTION ON POPs FORLATIN AMERICA AND THE CARIBBEAN REGION

V INTERNATIONAL TRAINING PROGRAM ON ENVIRONMENTAL SOUND MANAGEMENT ON CHEMICALS AND WASTES, ESPECIALLY ON PERSISTENT

ORGANIC POLLUTANTS (POPs) AND MERCURY (Hg)

Sediment QualityDr. José Eduardo Bevilacqua

2016

Sao Paulo – SP – Brazil

TOPICS

• DEFINITIONS • QUALITY CRITERIA• MONITORING NETWORK• SOME RESULTS AND INTERPRETATIONS• MANAGEMENT

The characterization of the quality of sediments is usually carried out in areas withhigh potential for contamination and low frequency, making return visits, to establishthe evolution of the quality of these environments.

Example of such activities is made, for example, by the USGS.

The network quality of sediment of São Paulo, established in 2002, is very important inassessing the quality of water, lentic and lotic environments, especially with respect tochemicals associated with polluting activities of large environmental impact.

It is also important to assess whether the pollution control measures effectivenessreached by the environmental agency

INTRODUCTION

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Industrial

In Industrialization

Environmental Conservation

Agricultural

THE STATE OF SÃO PAULO – VOCATIONAL UNITS

The state of São Paulo

BIOAVAILABILITY

M M+n

Inert forms Labile forms

Metals in sediment – Dependence of EH and pH

Surface Intertitial

+ H

Adsortion and complexation processes

Adsorption

Chemical Complexation

BIOGEOCHEMICAL CICLE OF MERCURY IN ENVIRONMENT

Organic Substances in sediment

The xenobiotic organic compounds are present due to the contribution of pollution sources, point and diffuse.

Typically they are present at levelssub-ppb (µg/kg)

They can be highly persistent or not, promoting biological effects of bioavailability and bioaccumulation bodies and man

These substances generally have low solubility in water (nonpolar) constituting a lipophilic character (solubility in adipose tissue) and thereby, the specific mechanism of transfer to biota.

PATHWAYS

Therefore, the quality of the sediment should be evaluated along the lines of chemical evidence, biological and ecotoxicological.

Conclusion

SEDIMENT QUALITY CRITERIA

SEDIMENT QUALITYDeterminations of the concentrations of chemical species present in sediments are important for two aspects: a) assess the possible accumulation of pollutants, which can originate from direct sources (point) and diffuse (urban and agricultural) and b) classify the sediments according to toxic effects expected, based on TEL values (threshold effect) and PEL (severe effect).

The following substances are evaluated:Metals: Cd, Cu, Cr, Pb, Ni, Hg, Zn and As.Organic compounds: Organochlorines (from industrial sources such as HCB, PCBs, pesticides like DDT, DDE, Lindane); Polycyclic Aromatic Hydrocarbons (PAHs) such as benzo (a) pyrene, dibenzo (a, h) anthracene, and the like.

Based on total concentrations and likelihood of deleterious effect on biota, the lowest limit (TEL), represents the concentration below which are rarely expected deleterious effects on organisms.

The higher limit (PEL) is the concentration above which it is often expected adverse effect on organisms.

In the range between TEL and PEL there are the values that occasionally such effects are expected.

The adoption of these values had character only as a guide in the search for evidence of the presence of contaminants in concentrations capable of causing harmful effects, especially regarding toxicity to biota.

SEDIMENT QUALITY

QUALITY EVALUATION CRITERIA OF SEDIMENT NETWORK

Since 2010, CETESB adopted the quality assessment represented sediment depending on the concentrations of contaminants, for the protection of aquatic life, based on the guide values set by the "Canadian Council of Ministers of the Environment" (CCME, 2002) for arsenic heavy metals and organic compounds, using five classes

The generation of data over five years has allowed the refinement of the quality diagnosis in five quality classes as well as the values of TEL and PEL, which were used to delimit rating bands.

A GREAT quality for each contaminant, is the concentration less than TEL.

The GOOD quality, the range between TEL, inclusive, and the concentration corresponding to 50% ofdistance between TEL and PEL, added to TEL.

The REGULAR quality, superior range to 50% of the distance between TEL and PEL, coupled with TEL and lower the PEL.

BAD quality, range of PEL, inclusive, and the concentration corresponding to 1.5x of its own value.

The quality VERY BAD above 1.5 x PEL.

Consider the following situation: 3 of 6 samples of sediments in a given area in a reservoir are contaminated by Cd, Cu and Hg, at levels above the TEL. Such samples have the following characteristics:

2 of 3 samples are contaminated percentage composition silt + clay fraction lower than 10%;Contaminated stretch is located in the center of the vessel;The redox potential values are all less than - 250 mV.

Establish an action plan regarding the quality of these sediments and possibleb) measures to be taken regarding these materials.

CHALLENGE

Based on the quality map displayed on the slide end of the class 2, perform a critical analysis of these sediments, considering the chemical, ecotoxicological and biological aspects and possible measures to be taken aiming at improving the quality of this environmental compartment.

CHALLENGE