List of Abbreviations

BCF

Bioconcentration factor

BDE

Bromo diphenyl ether

BDEs

Bromo diphenyl ether isomers

BMP

Best Management Practice

CB

Chlorinated biphenyl

CCME

Canadian Council of Ministers of the Environment

DDD

Dichlorodiphenyldichloroethane

DDE

Dichlorodiphenyldichloroethylene

DDT

Dichlorodiphenyltrichloroethane

DDTs

Dichlorodiphenyltrichloroethane isomers

ERL

Effects Range Low

ERM

Effects Range Median

HCH

Hexachlorocyclohexane

HCHs

Hexachlorocyclohexane isomers

HMW

High Molecular Weight

LMW

Low Molecular Weight

OCP

Organochlorine Pesticide

OCs

Organochlorines

op'-DDD

op'-dichlorodiphenyldichloroethane

op'-DDE

op'-dichlorodiphenyldichloroethylene

op'-DDT

op'-dichlorodiphenyltrichloroethane

pp '-DDE

pp'dichlorodiphenyldichloroethylene

PAH

Polycyclic Aromatic Hydrocarbon

PAHs

Polycyclic Aromatic Hydrocarbon isomers

PBDE

Polybrominated diphenyl ether

PBDEs

Polybrominated diphenyl ether isomers

PCB

Polychlorinated biphenyl

PCBs

Polychlorinated biphenyl isomers

PCDD

Polychlorinated dibenzodioxins

PCDD/Fs Polychlorinated dibenzo-p-dioxins and dibenzofurans

PCDD/Fs Polychlorinated dibenzo-p-dioxins and dibenzofurans

PEL Probable Effects Level

POP Persistent Organic Pollutant

POPs Persistent Organic Pollutant isomers pp'-DDD pp'-dichlorodiphenyldichloroethane pp'-DDE pp'-dichlorodiphenyldichloroethylene pp'-DDT pp'-dichlorodiphenyltrichloroethane

SQG Sediment Quality Guideline

TEL Threshold Effects Level

UNEP United Nations Environment Program

USEPA US Environment Protection Agency

10.1 Introduction

Persistent organic pollutants (POPs), a group of xenobiotic lipophilic pollutants, are semivolatile, bioaccumulative, persistent and toxic (Jones and de Voogt 1999). Organochlorines (OCs) such as PCBs and chlorinated pesticides (such as HCHs and DDTs), PAHs and PBDEs represent an important group of POPs that have caused worldwide concern as toxic environmental contaminants. In 2001, the Stockholm Convention on POPs acknowledged these as global problems. Although the occurrence of POPs at elevated levels is of great environmental concern at contaminated hot spots, the regional and global significance of the problem has received increased attention in the last decades (UNECE 1998; UNEP 2001). They have been reported to cause variety of effects including immunologic, teratogenic, carcinogenic, reproductive and neurological problems in organisms (Kodavanti et al. 1998) and are of considerable concern to human and environmental health. In addition, some congeners have shown some effects on the endocrine system such as reducing serum concentrations of the thyroid hormones like thyroxine and triiodothyronine (Koopman-Esseboom et al. 1994). The liphophilic nature, hydrophobicity and low chemical and biological degradation rates of these xenobiotics have led to their accumulation in biological tissues and a subsequent magnification of concentrations in organisms progressing up the food chain. Individual POPs have characteristic patterns of distribution depending on regional patterns of usage and their physico-chemical properties. Considering the global distribution of POPs it is important to understand their transport mechanism and to identify any hot spots where regulatory and remediation efforts are required. To evaluate the effectiveness of the regulations and remediation, monitoring of POPs is essential and the importance of global monitoring of POPs was emphasized at the Stockholm Convention (Secretariat of the Stockholm Convention).

India is one of the few remaining countries still engaged in the large scale manufacture, use and export of some of the toxic chlorinated pesticides, such as DDT), hexachlorocyclohexane (HCH) and pentachlorophenol (PCP). Even in the

1990s more than 70% of the gross tonnage of pesticides used in agricultural applications in India consisted of formulations which are banned or severely restricted in the east and west (Gupta 1989,1986,1985; Shetty 2001; Subramanian et al. 2007). According to a Green Peace Report, India is now producing 90,000 metric tons of pesticides as the largest industry in the whole of Asia and twelfth largest in the entire world (http://www.greenpeaceindia.org.nopesti.htm). The cumulative consumption of the pesticide, HCHs in India until 1985 was 5,75,000 tons and since then about 45,000 tons of HCHs has been used annually. The usage of DDT and HCH continued till recently. Apart from the US, India is the only country which has applied more than 1,00,000 tons of DDTs since its formulation, mainly in its agricultural and malarial control programs until it was banned for agricultural use in 1989. Even though usage of technical HCH was finally banned completely in 1977, the Government of India is encouraging its replacement with Lindane (g-HCH), an isomer which has all the hazardous properties of HCH. Even though DDT has been banned for agricultural use, India has sought exemption under Stockholm Convention for use of 10,000 tons of DDT for restricted use in the public health sector (Lallas 2001). The national malaria program (NAMP) used 3,750 tons of DDT in the year 2001, in rural and peri-urban areas for residual spraying (Gupta 2004).

India has a coastline of about 7,555 km, of which about 5,400 km belong to peninsular India and the remaining to the Andaman, Nicobar and Lakshadweep Island. With less than 0.25% of the world coastline, India houses 63 million people, approximately 11% of global population living in low lying coastal areas. The coast also includes 77 cities, including some of the largest and most dense urban agglomerations - Mumbai, Kolkata, Chennai, Kochi and Visakhapatnam (Fig. 10.1). India's coastal zone is endowed with a wide range of mangroves, coral reefs, sea grasses, salt marshes, sand dunes, estuaries, lagoons, and unique marine and terrestrial wildlife. The abundant coastal and offshore marine ecosystems include 6,740 km of mangrove belts, including part of the Sundarban (West Bengal) and the Bhitarkanika (Orissa), which are among the largest mangroves in the world. Rapid urban-industrialization, maritime transport, marine fishing, tourism, coastal and sea bed mining, offshore oil and natural gas production and aquaculture cause severe environmental degradation. A significant ecological change is pronounced in this coastal region due to contamination of inorganic and organic pollutants originated from huge discharge of domestic and industrial effluents carried by the rivers, disposal of contaminated mud from harbor dredging, intense shipping activities, agricultural runoffs, oil spills, deforestation, ill-planned river basin developments as well as atmospheric depositions. The present chapter attempts to elucidate the distribution, behavior and fate of these compounds in Indian coastal regions which are characteristically different in geomorphological and hydrological set up with varying anthropogenic stresses. The Arabian Sea and the Bay of Bengal (Fig. 10.1) are subject to semidiurnal tides and are also influenced by biannual reversal of the monsoon winds. These two factors result in the flushing of Indian coastal regions which help in dispersing pollutants.

Fig. 10.1 Map showing the distribution of major rivers, important coastal cities and mangrove areas in the east and west coast of peninsular India. The map of southeast Asia shows important locations as referred in the text

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