Chemosphere 137 (2015) 122–134
Contents lists available at ScienceDirect
Chemosphere journal homepage: www.elsevier.com/locate/chemosphere
Review
Recent status of organohalogens, heavy metals and PAHs pollution in specific locations in India Annamalai Subramanian ⇑, Tatsuya Kunisue, Shinsuke Tanabe Center for Marine Environmental Studies, Ehime University, Matsuyama, Japan
h i g h l i g h t s Pollution by organohalogens, metals, PAHs, etc. in India is updated. Spatial and temporal variations were observed in the last decade. Solid waste and ewaste dumping sites were prominent sources of pollution. Metro-cities in India also have high levels of certain chemicals. Coastal line sites seem to be less polluted than nearby inland areas.
a r t i c l e
i n f o
Article history: Received 17 February 2015 Received in revised form 21 June 2015 Accepted 22 June 2015
Keywords: India Organohalogens Heavy metals PAHs Recent status
a b s t r a c t Our group of scientists at the Center for Marine Environmental Studies (CMES), Ehime University, Japan has been carrying-out studies in India from the 1980s on chemicals contamination. Due to its agrarian economy, use of fossil fuels, industries, growing population and urbanization, chemicals such as pesticides, dioxins and related chemicals (DRCs), brominated flame retardants (BFRs), heavy metals, and polyaromatic hydrocarbons (PAHs) are widely spread in India. We have published a review (Subramanian and Tanabe, 2007) covering papers published until 2005, on India. A decade had passed and this is the time to provide an update of the spatial and temporal changes during this period and hence this review. At many instances organochlorines such as DDTs and HCHs showed decreasing trends even though they are still at considerable levels. Novel chemicals such as PCDDs/Fs are seen at municipal solid waste dumping sites of India at levels equivalent to similar locations of the developed world. In the e-waste processing sites in India, especially the informal ones, apart from PCDDs/Fs, some brominated flame retardants (BFRs) and heavy metals were present as contaminants. Metro cities of India showed location specific contamination by HCHs, DDTs, PCDDs/Fs, BFRs, PAHs, etc. Coastal regions of India seem to be still unpolluted when compared to the nearby inland locations. This review is concerned mainly with the chemicals that we (CMES) have been evaluating in India in the past three decades. We suggest the importance of further studies, future directions for policy decisions and also for implementing control measures. Ó 2015 Elsevier Ltd. All rights reserved.
Contents 1. 2.
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Recent status of organohalogen pollution in the municipal solid waste dumpsites in India . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.1. Organohalogens in the soil samples of municipal solid waste dumping sites of India. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.2. Organohalogens in the human breast milk samples collected from municipal solid waste dumping sites of India. . . . . . . . . . . . . . . . . . 2.3. Organohalogens in the wildlife samples collected from municipal solid waste dumping sites of India . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.3.1. Organohalogens in crows from Indian dump site. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.3.2. Organohalogens in pigs from Indian dump site . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.4. Concern over organohalogens in the dumping sites in India . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
⇑ Corresponding author at: Department of Environment Biotechnology, Bharathidasan University, Tiruchirappalli, India. E-mail address: [email protected] (A. Subramanian). http://dx.doi.org/10.1016/j.chemosphere.2015.06.065 0045-6535/Ó 2015 Elsevier Ltd. All rights reserved.
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3.
4.
5.
6.
Recent status of pollution in the e-waste recycling sites in India. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.1. Recent status of organohalogen pollution in ewaste recycling sites in India . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.2. Recent status of heavy metal pollution in ewaste recycling sites in India . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Recent pollution status in the major metropolitan cities of India . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.1. Recent status of organohalogen pollution in the major metropolitan cities in India . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2. Recent status of PAHs pollution in the major metropolitan cities in India . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Recent studies on the pollution in the coastal length of India . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.1. Recent status of organohalogen pollution in the air samples collected along the coastal length of India . . . . . . . . . . . . . . . . . . . . . . . . . 5.2. Recent status of organohalogen pollution in the mussel samples collected along the coastal length of India . . . . . . . . . . . . . . . . . . . . . . 5.3. Recent status of organohalogen pollution in the marine mammal samples collected along the coastal length of India . . . . . . . . . . . . . . Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1. Introduction The monitoring surveys of the Indian environment and biota by the CMES group started with the first sampling in December 1987 which has continued until the recent visit in September 2014. The samples collected in the trips to India comprised air, water, soil and sediments and also variety of tissues and organs of many animals including human. They were subjected to monitoring and toxicological studies on various organohalogen pollutants (e.g. DDTs, HCHs, CHLs, PCBs, PCDDs/DFs, PBDEs, HBCDs, OTs) and heavy metals. Few samples of road dust were also used for measuring the polyaromatic hydrocarbons (PAHs) in two major cities of India. The remaining samples after the intended analyses, numbering about 5000 are among the more than 100,000 samples collected from all over the world, are now archived in the Environmental Specimen Bank (es-BANK) of Ehime University, Japan (Tanabe, 2006). Published literature showed India as an important source among the Asian developing countries for the classical organochlorines such as DDTs, HCHs, and PCBs (Kannan et al., 1993; Babu Rajendran and Subramanian, 1997; Tanabe et al., 1998, 2000), even though their levels are decreasing in recent years. Some novel persistent chemicals like PCDDs/DFs and PBDEs were reported to be present in the Indian environment and biota in recent years (Someya et al., 2010; Eguchi et al., 2012, 2013; Devanathan et al., 2009, 2012; Tue et al., 2013). The entire literature, especially the data developed by our center, showed interesting spatial and temporal variations of these pollutants in the Indian environment. Viewing from the possibility of global transport of these pollutants from Indian sources and the necessity of consolidated recent information for scientists working on India’s pollution status and policy makers for planning and executing control measures to restrain the further expansion of contamination, we have gathered information from all our publications on India and also from other Indian and foreign authors and published an extensive review in the year 2007 (Subramanian and Tanabe, 2007), in which the data published by our group and others until the year 2005 were reviewed. After publishing the above review almost one decade has passed during which we have analyzed further Indian samples for studying the temporal variations of some of the old chemicals that we have been analyzing in the past and also extended our survey to more chemicals such as PCDDs/DFs some brominated flame retardants (BFRs) like PBDEs and HBCDs, heavy metals and also PAHs using appropriate samples. In recent years our surveys and sampling were mostly conducted in the specific environments such as municipal solid waste dumping sites and e-waste processing and recycling areas by collecting some specialized samples such as air, soil, fish, crow, pig, human milk, blood, hair and urine, house dust and road dust for the purpose of measuring some related chemicals released from and accumulated in those samples. We have gathered some data from the four major
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metropolitan cities and also along the coastal length of India both on the east and west coast, which showed area specific temporal and spatial changes. In the past decade, we have noticed changes in the Indian pollution scenario. The usage patterns of different chemicals for Indian agriculture and industries changed. Even though drastic changes did not occur in the public attitude, increase in the awareness on saving their own environment could be seen (Tanabe, 2000; Subramanian and Tanabe, 2007). People have become interested in greening the environment and they also take steps like segregating the wastes. The implementation of laws on environment has become stricter and the policy makers on environment take serious steps on environmental law breakers. At least some companies introduced voluntary steps on restricting and banning the use of some dreaded chemicals. Many backyard practices of waste processing have moved inside well organized recycling facilities, especially in the case of e-waste management (Eguchi et al., 2013). We have also seen temporal variations in the pollution scenario of Indian environment, especially in some specialized regions like municipal solid waste dumping sites, e-waste recycling, metropolitan cities and also in the coastal line of India. Effort by the scientific community in monitoring and controlling the above pollutants is improving obviously by way of encouragement by government and non-governmental organizations (Subramanian et al., 2007; Devanathan et al., 2012). As a result of these, the usage of different chemicals and hence the distribution pattern of pollutant chemicals in India changed a lot in recent years. So, provision of information on recent trends of pollution pattern of the above chemicals in India is the need of the hour and will be of intense help to those who are working on these lines. As a step towards this direction, this review gathers and provides information from the recent papers by our group on India after the publication of the previous review by Subramanian and Tanabe (2007), and also by other scientists in the contemporary India. The monitoring surveys on the pollution status of India from the CMES group after the preparation of the previous review (Subramanian and Tanabe, 2007) comprises work on some persistent organic pollutants in the environment and biota in and around the major cities (Subramanian et al., 2007, 2010; Devanathan et al., 2009), coastal areas (Kajiwara et al., 2006; Ramu et al., 2007), municipal solid waste dumping sites (Watanabe et al., 2005, 2010; Minh et al., 2006; Takahashi et al., 2006; Kunisue et al., 2006a; Mizukawa et al., 2010; Someya et al., 2010; Devanathan et al., 2012; Eguchi et al., 2013) and e-waste recycling areas (Eguchi et al., 2012; Tue et al., 2013; Takahashi et al., 2006) of India. Apart from these persistent compounds, there are publications on trace elements in e-waste processing areas (Ha et al., 2009) and polycyclic aromatic hydrocarbons in the road dust of two cities (Tuyen et al., 2014) which are also included in this review. We have had joint research ventures with groups outside
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Ehime University who published interesting papers on the pollution in India (Zhang et al., 2008; Paromita et al., 2010) and those papers are also cited and discussed in this review.
2. Recent status of organohalogen pollution in the municipal solid waste dumpsites in India In recent years (after 2000) our works centered on specialized environments such as municipal solid waste dumping sites and e-waste recycling sites in India. Specifically we have started monitoring the pollutants of recent interest such as PCDDs/Fs and the BFRs like PBDEs and HBCDs. When we started working on chemicals like organochlorine pesticides (OCPs), PCBs, PCDDs/Fs, PBDEs, HBCDs, etc. in the specialized environments in India after the year 2000, we selected the ambient soil, birds and human breast milk as our target samples and detected the existence of some of these organohalogen compounds in almost all the samples that we have analyzed (Watanabe et al., 2005, 2010; Minh et al., 2006; Takahashi et al., 2006; Kunisue et al., 2004a, 2006a,b; Ramu et al., 2007; Eguchi et al., 2009; Subramanian et al., 2007, 2010; Mizukawa et al., 2010, 2015; Someya et al., 2010; Eguchi et al., 2012; Devanathan et al., 2012; Tue et al., 2013).
2.1. Organohalogens in the soil samples of municipal solid waste dumping sites of India In a pioneering study from the municipal solid waste dumping sites in the Asian developing countries, possibly the first comprehensive study on PCDDs/DFs from India and surrounding countries, Minh et al. (2003) found that the residue levels of PCDD/Fs and co-planar PCBs in the dumping site soils in the suburbs of the major cities of some Asian developing countries like India (Chennai), Cambodia (Phnom Penh), the Philippines (Manila) and Vietnam (Hanoi) were higher than in the respective reference soils collected in agricultural or urban sites far from dumping sites. Further, the homologue profiles of the PCDDs/DFs in dumping soils from India, the Philippines and Cambodia reflected patterns representing typical emissions from municipal waste incinerators in developed nations while the profiles of agricultural soils in the developing countries were similar to typical environmental sinks like urban soils, sediments or atmospheric deposition soils in the developed nations thus suggesting recent formation of PCDD/Fs in municipal dumping site areas in Asian developing countries in Asian developing countries and also that these open dumping sites are potential sources of dioxins (Minh et al., 2003). Further, the authors calculated the loading rates of PCDD/Fs to a dumping site (annual amount of PCDD/Fs received by the surface area of the dumping site). The results showed that the fluxes to dumping site soils in the Philippines and Cambodia were greater than those from other locations in the world clearly supporting the fact that Asian dumping sites are sources of PCDD/Fs. The fluxes and toxic equivalents values (TEQs/yr) calculated by the authors indicated that the dumping sites that were surveyed for their study in Manila, the Philippines and Chennai, India with huge areas of approximately 23 and 140 ha could receive the highest annual amount of 3900 and 1400 mg/yr of PCDD/Fs resulting in the loading of 35 and 8.8 mg TEQs/yr respectively. The authors have also compared the TEQs in the Kanto region in Japan (one of the most polluted areas in the world where the estimated annual flux was in the range of 50–900 g TEQs). The Indian dumping site surveyed in the study by Minh et al. (2003) was 21,000 times smaller than the Kanto region but the annual flux is the range of 8.8 mg TEQs/yr. These estimation data suggest that
dumping sites in India and the Philippines may be a significant reservoir for PCDD/Fs (Minh et al., 2003). Interestingly, concentrations of PCDD/Fs in some soil samples from India analyzed in the study of Minh et al. (2003) were found to be higher than those reported in soils from Ohio, USA (mean concentration of 15,700 pg/g dry wt.), which was near a municipal solid waste incinerator emitting large amount of dioxins (1000 mg/yr). Similarly, an open landfill site in Crete, Greece, where uncontrolled low-temperature combustion was noticed for more than 10 yrs, has an extremely high concentration of PCDD/Fs (92,000 pg/g dry wt.) in a site close to the burning areas. Many cities in Asian developing countries do not have incinerators but resort to open dumping as they cannot afford to the high cost of incineration under high pressure and temperature. Among these, India is a very vast country and is disposing more than 50% of its domestic wastes in open dumping sites. The wastes are almost unsegregated comprising of over 50% organic matter, 17% recyclables, 11% hazardous and 21% inert material (Ministry of Environment, Government of India, 2010). There are licensed open dumpsites, maintained by the local governments in the outskirts of almost each city and also innumerable unlicensed sites spread all over the country. Apart from the classical organochlorines like OCPs and PCBs and also PCDDs/Fs, the BFRs like PBDEs and HBCDs were measured in the Indian dumping site soils (Takahashi et al., 2006; Eguchi et al., 2009, 2013) and milk from the women living near such places (Devanathan et al., 2012). These two chemicals are in use as flame-retardant additives in a wide variety of commercial and household products and the total usage of penta-, octa- and deca-BDEs and HBCDs in Asia during 2001 were 150, 2000, 23,000 and 3900 tons, respectively which have resulted in these classes of chemicals being present in air, water, soil and biota (Law et al., 2008). As wide variety of materials containing these chemicals are dumped there directly without any appropriate processing and segregation majority of these chemicals reach the municipal solid waste dumpsites in Asian developing countries (Minh et al., 2003). Presence of BFRs in Asian developing countries were already reported by a limited number of studies from China (Leung et al., 2007; Zou et al., 2007) and Indonesia (Ilyas et al., 2011). Takahashi et al. (2006) and Eguchi et al. (2009) published pioneering and preliminary reports on BFRs in the soil samples collected in the open dump sites, e-waste processing sites and other locations in India and compared the values with the analytical reports obtained from the samples from Cambodia and Vietnam. Following this, Eguchi et al. (2013) made an elaborate study on PBDEs and HBCDs using the archived soil samples at the Environmental Specimen Bank of Ehime University that were collected from six open dumping sites and five reference sites in India, Vietnam, Malaysia, Indonesia and Cambodia in the years 1999–2007. They found PBDEs in all the samples analyzed and also that the dumping site soils had significantly higher levels of this group of chemicals (P < 0.05) than the reference site samples from the respective countries indicating municipal dumpsites as sources of contamination by PBDEs in Asian developing countries. Among the countries evaluated, the highest values were found in Vietnam followed by Indonesia, Cambodia, India and Malaysia, in that order. The levels found in India were 0.82–19 ug/g dry wt. (mean: 7.3 ug/g dry wt.) in the dumpsite soil and
Contents lists available at ScienceDirect
Chemosphere journal homepage: www.elsevier.com/locate/chemosphere
Review
Recent status of organohalogens, heavy metals and PAHs pollution in specific locations in India Annamalai Subramanian ⇑, Tatsuya Kunisue, Shinsuke Tanabe Center for Marine Environmental Studies, Ehime University, Matsuyama, Japan
h i g h l i g h t s Pollution by organohalogens, metals, PAHs, etc. in India is updated. Spatial and temporal variations were observed in the last decade. Solid waste and ewaste dumping sites were prominent sources of pollution. Metro-cities in India also have high levels of certain chemicals. Coastal line sites seem to be less polluted than nearby inland areas.
a r t i c l e
i n f o
Article history: Received 17 February 2015 Received in revised form 21 June 2015 Accepted 22 June 2015
Keywords: India Organohalogens Heavy metals PAHs Recent status
a b s t r a c t Our group of scientists at the Center for Marine Environmental Studies (CMES), Ehime University, Japan has been carrying-out studies in India from the 1980s on chemicals contamination. Due to its agrarian economy, use of fossil fuels, industries, growing population and urbanization, chemicals such as pesticides, dioxins and related chemicals (DRCs), brominated flame retardants (BFRs), heavy metals, and polyaromatic hydrocarbons (PAHs) are widely spread in India. We have published a review (Subramanian and Tanabe, 2007) covering papers published until 2005, on India. A decade had passed and this is the time to provide an update of the spatial and temporal changes during this period and hence this review. At many instances organochlorines such as DDTs and HCHs showed decreasing trends even though they are still at considerable levels. Novel chemicals such as PCDDs/Fs are seen at municipal solid waste dumping sites of India at levels equivalent to similar locations of the developed world. In the e-waste processing sites in India, especially the informal ones, apart from PCDDs/Fs, some brominated flame retardants (BFRs) and heavy metals were present as contaminants. Metro cities of India showed location specific contamination by HCHs, DDTs, PCDDs/Fs, BFRs, PAHs, etc. Coastal regions of India seem to be still unpolluted when compared to the nearby inland locations. This review is concerned mainly with the chemicals that we (CMES) have been evaluating in India in the past three decades. We suggest the importance of further studies, future directions for policy decisions and also for implementing control measures. Ó 2015 Elsevier Ltd. All rights reserved.
Contents 1. 2.
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Recent status of organohalogen pollution in the municipal solid waste dumpsites in India . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.1. Organohalogens in the soil samples of municipal solid waste dumping sites of India. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.2. Organohalogens in the human breast milk samples collected from municipal solid waste dumping sites of India. . . . . . . . . . . . . . . . . . 2.3. Organohalogens in the wildlife samples collected from municipal solid waste dumping sites of India . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.3.1. Organohalogens in crows from Indian dump site. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.3.2. Organohalogens in pigs from Indian dump site . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.4. Concern over organohalogens in the dumping sites in India . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
⇑ Corresponding author at: Department of Environment Biotechnology, Bharathidasan University, Tiruchirappalli, India. E-mail address: [email protected] (A. Subramanian). http://dx.doi.org/10.1016/j.chemosphere.2015.06.065 0045-6535/Ó 2015 Elsevier Ltd. All rights reserved.
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3.
4.
5.
6.
Recent status of pollution in the e-waste recycling sites in India. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.1. Recent status of organohalogen pollution in ewaste recycling sites in India . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.2. Recent status of heavy metal pollution in ewaste recycling sites in India . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Recent pollution status in the major metropolitan cities of India . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.1. Recent status of organohalogen pollution in the major metropolitan cities in India . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2. Recent status of PAHs pollution in the major metropolitan cities in India . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Recent studies on the pollution in the coastal length of India . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.1. Recent status of organohalogen pollution in the air samples collected along the coastal length of India . . . . . . . . . . . . . . . . . . . . . . . . . 5.2. Recent status of organohalogen pollution in the mussel samples collected along the coastal length of India . . . . . . . . . . . . . . . . . . . . . . 5.3. Recent status of organohalogen pollution in the marine mammal samples collected along the coastal length of India . . . . . . . . . . . . . . Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1. Introduction The monitoring surveys of the Indian environment and biota by the CMES group started with the first sampling in December 1987 which has continued until the recent visit in September 2014. The samples collected in the trips to India comprised air, water, soil and sediments and also variety of tissues and organs of many animals including human. They were subjected to monitoring and toxicological studies on various organohalogen pollutants (e.g. DDTs, HCHs, CHLs, PCBs, PCDDs/DFs, PBDEs, HBCDs, OTs) and heavy metals. Few samples of road dust were also used for measuring the polyaromatic hydrocarbons (PAHs) in two major cities of India. The remaining samples after the intended analyses, numbering about 5000 are among the more than 100,000 samples collected from all over the world, are now archived in the Environmental Specimen Bank (es-BANK) of Ehime University, Japan (Tanabe, 2006). Published literature showed India as an important source among the Asian developing countries for the classical organochlorines such as DDTs, HCHs, and PCBs (Kannan et al., 1993; Babu Rajendran and Subramanian, 1997; Tanabe et al., 1998, 2000), even though their levels are decreasing in recent years. Some novel persistent chemicals like PCDDs/DFs and PBDEs were reported to be present in the Indian environment and biota in recent years (Someya et al., 2010; Eguchi et al., 2012, 2013; Devanathan et al., 2009, 2012; Tue et al., 2013). The entire literature, especially the data developed by our center, showed interesting spatial and temporal variations of these pollutants in the Indian environment. Viewing from the possibility of global transport of these pollutants from Indian sources and the necessity of consolidated recent information for scientists working on India’s pollution status and policy makers for planning and executing control measures to restrain the further expansion of contamination, we have gathered information from all our publications on India and also from other Indian and foreign authors and published an extensive review in the year 2007 (Subramanian and Tanabe, 2007), in which the data published by our group and others until the year 2005 were reviewed. After publishing the above review almost one decade has passed during which we have analyzed further Indian samples for studying the temporal variations of some of the old chemicals that we have been analyzing in the past and also extended our survey to more chemicals such as PCDDs/DFs some brominated flame retardants (BFRs) like PBDEs and HBCDs, heavy metals and also PAHs using appropriate samples. In recent years our surveys and sampling were mostly conducted in the specific environments such as municipal solid waste dumping sites and e-waste processing and recycling areas by collecting some specialized samples such as air, soil, fish, crow, pig, human milk, blood, hair and urine, house dust and road dust for the purpose of measuring some related chemicals released from and accumulated in those samples. We have gathered some data from the four major
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metropolitan cities and also along the coastal length of India both on the east and west coast, which showed area specific temporal and spatial changes. In the past decade, we have noticed changes in the Indian pollution scenario. The usage patterns of different chemicals for Indian agriculture and industries changed. Even though drastic changes did not occur in the public attitude, increase in the awareness on saving their own environment could be seen (Tanabe, 2000; Subramanian and Tanabe, 2007). People have become interested in greening the environment and they also take steps like segregating the wastes. The implementation of laws on environment has become stricter and the policy makers on environment take serious steps on environmental law breakers. At least some companies introduced voluntary steps on restricting and banning the use of some dreaded chemicals. Many backyard practices of waste processing have moved inside well organized recycling facilities, especially in the case of e-waste management (Eguchi et al., 2013). We have also seen temporal variations in the pollution scenario of Indian environment, especially in some specialized regions like municipal solid waste dumping sites, e-waste recycling, metropolitan cities and also in the coastal line of India. Effort by the scientific community in monitoring and controlling the above pollutants is improving obviously by way of encouragement by government and non-governmental organizations (Subramanian et al., 2007; Devanathan et al., 2012). As a result of these, the usage of different chemicals and hence the distribution pattern of pollutant chemicals in India changed a lot in recent years. So, provision of information on recent trends of pollution pattern of the above chemicals in India is the need of the hour and will be of intense help to those who are working on these lines. As a step towards this direction, this review gathers and provides information from the recent papers by our group on India after the publication of the previous review by Subramanian and Tanabe (2007), and also by other scientists in the contemporary India. The monitoring surveys on the pollution status of India from the CMES group after the preparation of the previous review (Subramanian and Tanabe, 2007) comprises work on some persistent organic pollutants in the environment and biota in and around the major cities (Subramanian et al., 2007, 2010; Devanathan et al., 2009), coastal areas (Kajiwara et al., 2006; Ramu et al., 2007), municipal solid waste dumping sites (Watanabe et al., 2005, 2010; Minh et al., 2006; Takahashi et al., 2006; Kunisue et al., 2006a; Mizukawa et al., 2010; Someya et al., 2010; Devanathan et al., 2012; Eguchi et al., 2013) and e-waste recycling areas (Eguchi et al., 2012; Tue et al., 2013; Takahashi et al., 2006) of India. Apart from these persistent compounds, there are publications on trace elements in e-waste processing areas (Ha et al., 2009) and polycyclic aromatic hydrocarbons in the road dust of two cities (Tuyen et al., 2014) which are also included in this review. We have had joint research ventures with groups outside
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Ehime University who published interesting papers on the pollution in India (Zhang et al., 2008; Paromita et al., 2010) and those papers are also cited and discussed in this review.
2. Recent status of organohalogen pollution in the municipal solid waste dumpsites in India In recent years (after 2000) our works centered on specialized environments such as municipal solid waste dumping sites and e-waste recycling sites in India. Specifically we have started monitoring the pollutants of recent interest such as PCDDs/Fs and the BFRs like PBDEs and HBCDs. When we started working on chemicals like organochlorine pesticides (OCPs), PCBs, PCDDs/Fs, PBDEs, HBCDs, etc. in the specialized environments in India after the year 2000, we selected the ambient soil, birds and human breast milk as our target samples and detected the existence of some of these organohalogen compounds in almost all the samples that we have analyzed (Watanabe et al., 2005, 2010; Minh et al., 2006; Takahashi et al., 2006; Kunisue et al., 2004a, 2006a,b; Ramu et al., 2007; Eguchi et al., 2009; Subramanian et al., 2007, 2010; Mizukawa et al., 2010, 2015; Someya et al., 2010; Eguchi et al., 2012; Devanathan et al., 2012; Tue et al., 2013).
2.1. Organohalogens in the soil samples of municipal solid waste dumping sites of India In a pioneering study from the municipal solid waste dumping sites in the Asian developing countries, possibly the first comprehensive study on PCDDs/DFs from India and surrounding countries, Minh et al. (2003) found that the residue levels of PCDD/Fs and co-planar PCBs in the dumping site soils in the suburbs of the major cities of some Asian developing countries like India (Chennai), Cambodia (Phnom Penh), the Philippines (Manila) and Vietnam (Hanoi) were higher than in the respective reference soils collected in agricultural or urban sites far from dumping sites. Further, the homologue profiles of the PCDDs/DFs in dumping soils from India, the Philippines and Cambodia reflected patterns representing typical emissions from municipal waste incinerators in developed nations while the profiles of agricultural soils in the developing countries were similar to typical environmental sinks like urban soils, sediments or atmospheric deposition soils in the developed nations thus suggesting recent formation of PCDD/Fs in municipal dumping site areas in Asian developing countries in Asian developing countries and also that these open dumping sites are potential sources of dioxins (Minh et al., 2003). Further, the authors calculated the loading rates of PCDD/Fs to a dumping site (annual amount of PCDD/Fs received by the surface area of the dumping site). The results showed that the fluxes to dumping site soils in the Philippines and Cambodia were greater than those from other locations in the world clearly supporting the fact that Asian dumping sites are sources of PCDD/Fs. The fluxes and toxic equivalents values (TEQs/yr) calculated by the authors indicated that the dumping sites that were surveyed for their study in Manila, the Philippines and Chennai, India with huge areas of approximately 23 and 140 ha could receive the highest annual amount of 3900 and 1400 mg/yr of PCDD/Fs resulting in the loading of 35 and 8.8 mg TEQs/yr respectively. The authors have also compared the TEQs in the Kanto region in Japan (one of the most polluted areas in the world where the estimated annual flux was in the range of 50–900 g TEQs). The Indian dumping site surveyed in the study by Minh et al. (2003) was 21,000 times smaller than the Kanto region but the annual flux is the range of 8.8 mg TEQs/yr. These estimation data suggest that
dumping sites in India and the Philippines may be a significant reservoir for PCDD/Fs (Minh et al., 2003). Interestingly, concentrations of PCDD/Fs in some soil samples from India analyzed in the study of Minh et al. (2003) were found to be higher than those reported in soils from Ohio, USA (mean concentration of 15,700 pg/g dry wt.), which was near a municipal solid waste incinerator emitting large amount of dioxins (1000 mg/yr). Similarly, an open landfill site in Crete, Greece, where uncontrolled low-temperature combustion was noticed for more than 10 yrs, has an extremely high concentration of PCDD/Fs (92,000 pg/g dry wt.) in a site close to the burning areas. Many cities in Asian developing countries do not have incinerators but resort to open dumping as they cannot afford to the high cost of incineration under high pressure and temperature. Among these, India is a very vast country and is disposing more than 50% of its domestic wastes in open dumping sites. The wastes are almost unsegregated comprising of over 50% organic matter, 17% recyclables, 11% hazardous and 21% inert material (Ministry of Environment, Government of India, 2010). There are licensed open dumpsites, maintained by the local governments in the outskirts of almost each city and also innumerable unlicensed sites spread all over the country. Apart from the classical organochlorines like OCPs and PCBs and also PCDDs/Fs, the BFRs like PBDEs and HBCDs were measured in the Indian dumping site soils (Takahashi et al., 2006; Eguchi et al., 2009, 2013) and milk from the women living near such places (Devanathan et al., 2012). These two chemicals are in use as flame-retardant additives in a wide variety of commercial and household products and the total usage of penta-, octa- and deca-BDEs and HBCDs in Asia during 2001 were 150, 2000, 23,000 and 3900 tons, respectively which have resulted in these classes of chemicals being present in air, water, soil and biota (Law et al., 2008). As wide variety of materials containing these chemicals are dumped there directly without any appropriate processing and segregation majority of these chemicals reach the municipal solid waste dumpsites in Asian developing countries (Minh et al., 2003). Presence of BFRs in Asian developing countries were already reported by a limited number of studies from China (Leung et al., 2007; Zou et al., 2007) and Indonesia (Ilyas et al., 2011). Takahashi et al. (2006) and Eguchi et al. (2009) published pioneering and preliminary reports on BFRs in the soil samples collected in the open dump sites, e-waste processing sites and other locations in India and compared the values with the analytical reports obtained from the samples from Cambodia and Vietnam. Following this, Eguchi et al. (2013) made an elaborate study on PBDEs and HBCDs using the archived soil samples at the Environmental Specimen Bank of Ehime University that were collected from six open dumping sites and five reference sites in India, Vietnam, Malaysia, Indonesia and Cambodia in the years 1999–2007. They found PBDEs in all the samples analyzed and also that the dumping site soils had significantly higher levels of this group of chemicals (P < 0.05) than the reference site samples from the respective countries indicating municipal dumpsites as sources of contamination by PBDEs in Asian developing countries. Among the countries evaluated, the highest values were found in Vietnam followed by Indonesia, Cambodia, India and Malaysia, in that order. The levels found in India were 0.82–19 ug/g dry wt. (mean: 7.3 ug/g dry wt.) in the dumpsite soil and
