Organic Pollutants

Persistent organic pollutants (POPs) are carbon-based pollutants existing in our environment for extended periods of time. POPs are of global concern due to their far-reaching presence in the environment. They are present in the lithosphere (soil), hydrosphere (water), biosphere (living beings), and atmosphere (air). Both natural and anthropogenic forms of POPs are known. POPs can be considered as “forever chemicals” as they are resistant to degradation in the ecosystem via biologically, chemically, and photolytically to varying degrees and as such are persistent in our environment. They have the ability to biomagnify via the food chain and can bioaccumulate in the various organisms in the ecosystem due to their high lipid solubility. They can be transported over long distances by water and wind and are found in many regions where there are no major sources of POPs. The comprehensive pollution of the environment and living organisms by POPs has resulted in acute as well as chronic toxic effects in many living species. Under the leadership of United Nations Environment Programme (UNEP), the Stockholm Convention of Persistent Organic Pollutants was held in 2001. In this treaty, 12 classes of organic chemicals (also referred as the “dirty dozen”) were identified as POPs. In this chapter, the source, structure, general characteristics, and uses of the intentionally produced and unintentionally formed “dirty dozen” will be disclosed. The major adverse effects caused by the “dirty dozen” on human health and the environment will be also summarized.

Persistent organic pollutants (POPs) are organic pollutants that exist for extended periods of time in our environment. Due to their ubiquitous presence in the environment (water, air, soil, and living beings), both natural and man-made forms of POPs are of global concern. They can be considered as “forever chemicals” due to their resistance to degradation in the ecosystem via photolytically, biologically, or chemically to diversified degrees. They have the potential to biomagnify via the food chain, and due to their high lipid solubility they can bioaccumulate in the various organisms in the ecosystem. They are transported beyond international borders by water and wind and are detected in places far from their sources. The comprehensive contamination of the living organisms and environment by POPs has resulted in acute as well as chronic toxic effects in many living species. Under the leadership of United Nations Environment Programme (UNEP), 12 classes of organic compounds (or the “dirty dozen”) were initially identified as persistent organic pollutants in the Stockholm Convention of Persistent Organic Pollutants held in 2001. In the subsequent Stockholm Conventions held biennially from 2009 to 2019, additional chemicals were considered as new POPs. In this chapter, the source, structure, general characteristics, and uses of the intentionally produced and unintentionally generated new persistent organic pollutants introduced from 2009 will be described. The major adverse effects caused by these new persistent organic pollutants on human health and the environment will be also summarized.

Due to increase in industrialization and rapid civilization, excessive numbers of chemicals are being discharged into the atmosphere. Persistent organic pollutants (POPs) are worldwide concern due to their widespread occurrence, enhanced persistence, distant transference, greater biomagnification and bioaccumulation which could affect the human health and other organisms in the ecosystems. Organic pollutants accumulating in aquatic sediments can adversely affect the benthic organisms, and the same can be thrown back into the ecosystem during resuspension and/or through the food chain from benthic to pelagic organisms and so on. This chapter summarizes the recent findings on the impact of existing and emerging POPs on ecosystem and various organisms including human. In recent years, some of the emerging contaminants including polybrominated diphenyl ethers (PBDEs) and perfluorooctane sulfonate (PFOS) are classified under POPs, and these contaminants have been widely reported in environment. Though the concentrations of emerging POPs in the environment are presently very low, it has been estimated that they would dramatically increase owing to social and economic development. The impact of these pollutants on humans varies from skin rashes to cancer. Congenital disorders and metabolic diseases due to POPs could have significant health impacts for future generations as well. This chapter also addresses studies looking at the relations between the exposure and consequences of POPs to human health emphasizing the impact of these pollutants with reference to their gender-specific effects. This chapter also reviews a wide array of methods which can be used as markers to identify the effect of persistent pollutants on different organisms. Biomagnification and bioaccumulation were used as a tool for revealing the impact on the aquatic systems. Overall, studies in this field relating to POPs are not abundant, and hence extensive studies need to be conducted to increase our understanding on the health and ecological consequences of these contaminants in order to devise strategies for not only preventing exposure but also for ecological remediation.

In the twenty-first century extensive use and production of hazardous chemicals referred as persistent organic pollutants (POPs) have raised significant concerns owing to their widespread environmental, health and ecosystem impacts. Although, the manufacture and usage of many POPs have been discontinued by many developed counties in many developing counties the usage and production of POPs is not as restricted. In the Caribbean region, POPs management efforts are problematical due to the lack of appropriate legislation and limitations in research and monitoring; hence these developing countries find it difficult to manage POPs and comply with international singed conventions. This poses a local, regional and global treat because of the POPs long-range transport characteristics. In an effort to have a more holistic perspective and a better understanding of the developments that have occurred subsequent to the approval of the Stockholm Convention this book chapter aims to discuss the types and impact of POPs, the analytical methods employed for the determination of POPs, the removal of POPs and an overview of POPs management in the Caribbean Region, specifically a case study of Belize.

Aldehydes are highly reactive carbonyl compounds that are widespread in the nature. Aldehydes are broadly distributed in the indoor and outdoor environment sourced from the industrial, restaurant, and motor vehicular exhausts. Besides, aldehydes are thought to be a major cause of the photochemical smog in the air. Aldehydes are also present in rainwater and the surface water due to their washing away from the atmosphere owing to their high-water solubility. In addition, microbial or photochemical degradation of organic chemicals leads to the formation of aldehydes in the surface water. Furthermore, chlorination and ozonation sterilization of drinking water lead to aldehydes’ formation. On the other hand, aldehydes could be formed during cooking upon high-temperature frying and also could be sourced from cigarette smoke and/or other combustion operations. Besides, aldehydes are present in wine and vegetable oils, and they are formed as by-products during deterioration, maturing, or microbial fermentation of food. Human exposure to aldehydes from the environment or food could bring many adverse health effects either acute or chronic ones. Aldehydes are highly reactive with biological molecules; thus, they are considered highly toxic. The aldehydes’ biochemical modification could lead to the disruption of biological functions, and consequently, cause many diseases. Thus, aldehyde monitoring in the surrounding environmental and food samples is vital to control the toxic aldehydes’ possible health risk on humans. Aldehydes’ different sources in the environment, molecular toxicity mechanisms, possible effects on human health, and recently developed analytical methods for determination and control of aldehydes in environmental and food samples will be summarized in this chapter.

A category of new chemicals, phthalic acid esters (PAEs), are used primarily as plastic additives that can be easily leached out of plastics and released into the environment and can create risks when exposed by the humans and other living organisms. The distribution and ecotoxicological risk assessments based on risk quotient (RQ) of six phthalic acid esters (PAEs) including dimethyl phthalate, diethyl phthalate, dibutyl phthalate, benzyl butyl phthalate, bis(2-ethylhexyl) phthalate, and di-n-octyl phthalate in surface water and sediment collected from the Kaveri, Vellar, and Tamiraparani Rivers, Tamil Nadu, India. As far our knowledge is concerned, this is the first comprehensive study that examines phthalate contamination seasonally in these three rivers. This chapter confirms ubiquitous phthalate contamination of fresh water ecosystems in India, and the data contribute for better understanding and managing the pollution from emerging contaminants.

Phenol is hydroxybenzene, an organic aromatic compound consisting of the attached hydroxyl group to aromatic hydrocarbon group. Phenol is hazardous to environment that is added mainly through wastes waters of textile, pharmaceuticals industries, and automobile waste. Phenolic compounds in the aquatic system harm flora and fauna of water bodies and they also interfere with biotransformation. Various forms of phenolic compounds influence the ozone layer, cause acid rain, and disturb the atmospheric temperature balance. Phenol is difficult to degrade, and hence, it is retained in air, soil, and water for a long period. Thus, for protection of the ecosystem and human health, it necessary to adapt effective strategies to eliminate the phenolic pollutant. This chapter depicts various physicochemical methods analyzed for degradation of phenol that include partial electrocatalytic degradation, photo-Fenton processes, electro-polymerization, and advanced nano systems. This chapter focuses on the relevant eco-friendly techniques such as adsorption, immobilization, and fuel cell technology using microorganisms employed for phenol removal and various physical, chemical, and biological factors evaluated by optimization studies designed using statistical tools for enhancing phenol degradation.

The usage of fertilizers and pesticides has increased to meet the increasing needs of exploding population. Pesticides refer to the chemicals which are widely used for destroying the pests that could affect the produce of the agricultural fields. One such organochlorine pesticide is lindane, which is widely employed all over the world. The pesticides and fertilizers applied to the fields with an intention to destroy the pests and to increase the production respectively result in the ground water pollution due to the leaching of the compounds and pave way for surface water pollution contaminating the rivers, lakes, and reaches the sea too. Not only the water gets polluted, the soil also gets polluted. However, the rate of degradation of the compound of interest, namely, lindane is of utmost importance as it makes us understand the time for which the risk exists with the exposure to the compound.

Hence, this chapter elucidates the details on lindane-contaminated soil and water ecosystems and the remediation strategies that can be implemented. However, the natural microbiota present in the lindane-contaminated ecosystems is continuously exposed to this pesticide. So, one could expect that the microorganisms that inhabit in such polluted environments are equipped with the resistance and would be capable of removing the toxic compounds. As it is proved that the process of bioremediation is an effective strategy for the removal of many number of xenobiotics, it could be an effective solution for lindane pollution too. This chapter also intends to explain the potential of certain microorganisms which could facilitate the degradation of lindane.

A disinfectant is a chemical agent and constitutes different group of products used to control the microorganisms in all surfaces except animates. These chemical compounds exterminate most of the pathogens excluding bacterial spores, a few will kill spores that lengthen the timing according to its vulnerability. Disinfectants were predominantly used in hospitals, industrial and institutional settings, but recently the usage of disinfectants reaches each and every house to get rid of communicable diseases. It is highly recommendable to have knowledge on proper usage of disinfectants, type of chemicals, and its concentration; otherwise, it will cause a severe health damage in humans from irritation in the eye and skin to acute, chronic defects in respiratory, nervous system, and even cancers. Government regulations require only limited labelling of cleaning products for the purpose of marketing. Hence, business people recognized the explicit loopholes in understanding fundamental information, choice and utilization of items and practices, risk correspondence, and more secure alternatives. This chapter bridges the gap by creating a clear understanding on classification of disinfectant, considerations, assessment, and implementation for a disinfection action plan, concentration of disinfectant, application methods, and contact time. This chapter also emphasizes, how overexposure or improper usage of disinfectant causes symptomatic and asymptomatic health hazards in humans and also creates awareness on clear management of disinfectants among the disinfectant handlers, health care workers, and public.

The most crucial challenge of the twenty-first century is water management. In India, only about 38% of the urban population has access to sanitation services. Urban planners are facing dual problems of providing safe drinking water and sanitation facilities. Our existing sewage treatment plants (STPs) are designed for the removal of organic, grit, coarse materials; floating matter; suspended solids; and to some extent, destruction of pathogens in case used for horticulture/agricultural purpose.

Pharmaceuticals and personal care products (PPCPs) or micro-pollutants are classified as emerging contaminants (ECs) because of associated endocrine disruption, chronic toxicity, and the development of resistance to pathogens. The presence of micro-pollutants also endangers the reuse of treated domestic sewage. So far, there is no focus on ECs being either identified or investigated for their removal through conventional wastewater treatment plants. The key sources of PPCPs entering the water environment are excretion, domestic sewage, and direct disposal.

A few studies have been carried out on PPCPs in countries such as Korea, Sweden, the UK, China, Austria, the European Union, Germany, France, Italy, Greece, Switzerland, Spain, the Western Balkan Region, and the USA. In India, knowledge about the load of PPCPs entering into STPs and their removal efficiencies in existing treatment facilities is low.

PPCPs and antibiotics entering water bodies lead to severe ecological damage and potential adverse effects on the existing treatment facilities. Thus, treatment facilities should be concentrated to improve removal efficiencies of antibiotics in STPs. The primary focus of this chapter is to discuss the following in detail: (i) the sources of generation of micro-pollutants or PPCPs, (ii) existing scenario in regard to the level of occurrence of PPCPs in STPs, (iii) significant effect of their presence on the environment, and (iv) treatment options proposed/studied so far and additional treatment facilities required to destruct these pollutants, in a form of review to enable the policy makers to address these issues in future.

Triclosan is a nonionic, phenolic, antimicrobial compound that is used all over the world, as a key ingredient in pharmaceutical and personal care products (PPCPs) such as disinfectants, soap, detergent, toothpaste, mouthwash, fabric, deodorant, shampoo, and plastic additives. It causes a range of adverse effects in animals and has a great impact on environment also. This chapter investigates the effect of triclosan in varying concentrations and triclosan-contaminated soil by using earthworms as bioindicators. The effects were calculated by analyzing their antioxidative enzymes and DNA damages. The antioxidant enzymes were estimated by analyzing the antioxidant properties of earthworm which include glutathione peroxidase and catalase. Comet assay was done to monitor the DNA damage of the earthworms with regard to triclosan toxicity. The investigation proves that when the concentration of triclosan increases, the effects in the earthworms were also radical. This study thus denotes that triclosan induces adverse consequences on earthworms which sever the antioxidant enzyme mechanisms and DNA damage.

Medicines are immensely playing an essential role in protecting human and animal health. Pharmaceuticals are categorized into myriad therapeutic divisions, including anti-inflammatories, antibiotics, antipsychotics, antihypertensives, antidiabetics, antihistamines, lipid regulators, anticonvulsant, β-blockers, stimulants and statins. This chapter is aimed to offer a brief overview on the origin of pollutants of antibiotic and anti-inflammatory medicines and their brief toxicity hazards to human and aquatic life. Due to the high prevalence of infectious diseases, antibiotics and related by-products are one of the major pharmaceutical pollutants. Non-steroidal anti-inflammatory drugs (NSAIDs) are customarily being used and consequently are perceived in effluent and wetland water and may be found in groundwater systems. There are growing environmental concerns and excessive usage of medicines emerging as contaminants when their residues enter freshwater systems. Overwhelmed use of pharmaceuticals showed impact on aquatic and terrestrial living beings as well as the environment.

As a consequence of industrial development, effluents from various industrial practices augmented the concentration of environmental contaminants on the earth’s surface. Therefore, the materials adopted for decontamination of these environmental contaminants must be environmentally safe and could not produce any toxic side effects to any component of the living organism. In reality, nanoscience and nanotechnology offered the greatest efficiency for the removal of perilous environmental contaminants, and toxicological effects resulted due to the unsafe disposal of these nanoparticles, nanomaterials, and nanocomposites. Herein, we discuss biological and chemical treatment technologies for the mineralization of various environmental contaminants and nanocatalysts’ efficiency toward their complete removal. The second part of this chapter essentially concentrated on toxicological effects generated by the unsafe disposal of nanomaterials/nanocatalysts to the environment. Two noteworthy components of the food cycle are plants and fishes; accumulation, translocation, and biotransformation of nanoparticles/metals/semiconductor nanocomposites in the food cycle are discussed for a better understanding of the underlying relation between catalytic and toxicological effects of nanomaterials.

Bioremediation is an alternative, sustainable, renewable, cost-effective, and ecofriendly process for industrial effluent treatment rather than unsustainable, non-renewable, costlier, and non-eco-friendly conventional methods of effluent treatment. Therefore, bioremediation is a boon to all the industries to control the pollutant levels in effluents after treatment and before discharge to the environment. Some of the significant effluent-producing industrial sectors are petrochemical, agrochemical, food, tannery, domestic sewage, and nuclear power. Among different types of bioremediation, phycoremediation has evolved to commercial scale, industrial bioremediation plant and ensures potential in removing pollutants and simultaneously serves in clean energy technology. Phytoremediation using terrestrial green plants is familiar and favorable for mass-scale in situ bioremediation strategy. Bioaugmentation and biostimulation are the most critical processes for selecting an indigenous or consortium of microbes and providing favorable nutrients, respectively, to enhance and evolve microbial bioremediation. Bioengineering is a powerful tool for the synthesis of efficient biocomponent with desired traits to enhance bioremediation. Designing bioreactors for indigenous microbes or consortium of a microbial system is fruitful in bioremediation strategy. For example, tubular photobioreactors are designed especially for the microalgal system for efficient bioremediation strategy in industries followed by the production of value-added by-products. However, an integrated bioremediation strategy will be efficient in the future by coupling anaerobic, aerobic, photoautotrophic, followed by terrestrial and aquatic green plants in a series of wastewater treatment measures to efficiently reduce pollutants in all the stages.

Many pharmaceutical companies utilize confidentiality composition as a means to escape the norms imposed by the pollution regulation control. Derivatives of pharmaceutical compounds (hormones, volatile organic compounds, antibiotics, and surfactants) and their metabolites are toxic (ecosystem of aquatic, terrestrial, and human health), and antibiotic-resistant microbial species are wastewater sources from houses, pharmaceutical industry, and hospitals. The wastewater comprises large quantity of salt, organic matter, microbial toxicity creating COD and BOD, and ever-increasing innovations in the field of medicine also increases the usage of pharmaceutical drugs, thereby increasing the rate of pollution. Pollution begins from the production and processing of pharmaceutical products until the cycle of consumption. This chapter explicates pharmaceutical contamination and pollution created by personal care products and addresses the means of elimination by biological and chemical methods like adsorption / bioadsorption, activated carbon adsorption, sedimentation, coagulation, advanced oxidation processes, photooxidation, ozonation, biological treatment, and electrochemical processes. Eco-friendly approaches are derived from the biological treatment by microbial process (composting, vermicomposting, aerobic and anaerobic techniques), and they do not produce secondary waste and also convert the toxic to non-toxic form. This has also demonstrated the benefits and demerits of the removal measures. This chapter summarizes the important overviews of key publications on pharmaceutical products.

Bioremediation techniques have become noticeable and valuable tools to reduce, reuse, and recycle different industrial effluents through eco-friendly practices. Industries are well known to release anthropogenic-related chemicals into the environment over the century and consequences are witnessed as contamination of soil, water, and air, respectively. The untreated or impertinently treated wastewater effluents are known to be toxic to plants and animals, including humans that lead to negative impacts on the earth. Remediation has emerged for degrading contaminants using physical, chemical, and biological methods. Bioremediation techniques are used nowadays around the world meticulously. It is technology based along with the combined action of plants and associated microbial communities to degrade, remove, transform, or immobilize toxic compounds in effluents. This chapter discusses the classes of organic effluents, toxicological mechanism, and its environmental impact and also emphasizes the current and advanced eco-friendly techniques in the remediation of organic effluents through microbial, algal bioremediation and phytoremediation. Bioremediation techniques are potential, cost-effective, and in addition to that remains as a solution to the challenge of treating many classes of contaminants, compared to the conventional chemical and physical methods, which are often very expensive and ineffective compared to biological methods.

Textile industries play a crucial role in Indian economy and also cause serious issues on environmental pollution. The demand of colors, fade-resistant garments, and other hue products are increasing in day-to-day lifestyle, triggering the blooming of dyeing industries. These factories utilize colossal volume of water and various chemical substances for dyeing process and release toxic organic pollutants such as organic azo-dyes, surfactants, and phenolic compounds with effluent to the environment which severely disturb the natural balance and affect all forms of living beings. Higher concentration of colored compounds in the effluent mixed with surface water reduces the flow of sunlight and prevents the photosynthetic process of aquatic vegetation. Also, it affects the fertility of agricultural land and health impacts in human and animals. The changes in physicochemical nature of surface and underground water quality due to textile effluent lead to water crisis. Conventional treatment methods are expensive and not sufficient in efficient removal of organic pollutants from the wastewater. Thus, economically and ecologically safe approaches are needed for the treatment of textile industry effluent to prevent and conserve natural resources without affecting the growth of this sector. In this chapter, eco-friendly techniques such as bioremediation, phytoremediation, coagulation process by natural coagulants, and biogenic nanomaterials applied for the removal of organic pollutants from the textile effluent are elaborately discussed.

The industrial effluents are being discharged into the adjacent water bodies without proper treatment. Such effluents contain excessive nutrients, heavy metals, toxic compounds, and non-biodegradable materials which could harm the aquatic environments and their associated flora and fauna. In this chapter, the recent technologies that have been applied to eliminate and/or used to remove excessive nutrients in water ecosystems are discussed with special reference to microalgae. The survey of literature indicates that the microalgae have been used via a wide range of absorption and adsorption methods toward removing the excessive nutrients from the effluents. The use of living cells or dry biomass of microalgae as compared to other currently employed ones toward nutrient removal has been an advantageous one. This chapter discusses the process and enforcement necessities to bring the excess nutrients elimination more possible at a commercial level.

Globally the huge amount of solid waste creates the ecological and technical problems. As the human population increases, there is simultaneously increase in waste generation. Hence waste management strategies are considered most important in gaining organic nutrients from it. Farmyard manure, biochar, poultry manure, vermicompost, biogas digest, and urban compost are rich sources of vitamins, growth-promoting substances, macro-, and micro-nutrients. Numerous technologies are followed nowadays to recover organic nutrients and utilize them for the agricultural field to retain the soil fertility, improved tillage, reduce irrigation of soil, obtain high porosity, better aeration, water holding capacity, and plant growth-promoting factor, etc. Among them composting, vermicomposting technologies, and aerobic digestion play major roles. These processes are able to collect microbes, macro-nutrients, and all micro nutrients from the waste degradation. At the end of process, compost and digestate obtained are eco-friendly and cost-effective compare to other bio products. This chapter deliberates the methods followed in managing solid waste and their importance in gaining nutrients. This could also substantiate the significance of micro- and macroorganism helpful in increasing the rate of degradation. Other new technologies such as biochar, osmosis, and electro-dialysis are also discussed. This chapter summarizes over all case studies and key publications regarding solid waste management and nutrient recovery from organic waste with no further costs.

Plastics are inert materials that are resistant to environmental and mechanical stress. The immense use of plastics has increased over the past decade. In addition, utilization of non-degradable polymers showed the impact on health of the terrestrial and aquatic lives. In general physical or chemical recycling process, which reduces the accumulation of plastic wastes while the decomposition of the plastics was majorly attained by the process of incineration. Pyrolysis, chemical degradation, and biological degradation are widely explored methods to reduce the precipitation of polymer waste. Energy recovery through chemo-pyrolysis of plastics aids by the chemical degradation to produce liquid fuel, wax, and other by-products which might be used in various applications. The depolymerized plastics can be made into a value-added product by combining it with biodegradable substance which changes the physical and chemical characteristics of plastics. The current management of plastic waste might be a tentative relief, but we need a completely sustainable solution. This chapter is intended to combine chemical and biological methods developed for plastic waste management.

Pesticides are chemicals that are used to kill pests. Partition coefficient in n-octanol and water distribution (log P_o/w) is one of the useful parameters to understand mobility in biological systems. This chapter consists of a short review of the experimental and computational methods used for the determination of log P_o/w. It also includes the application of density functional theory (DFT) method to calculate the log P_o/w for 23 pesticides. A comparison of the computed and reported log P_o/w of these pesticides resulted in R² = 0.88, and it improved to 0.96 after excluding two outliers. The findings from this work can be useful to compute log P_o/w of novel pesticides.

Microplastics are small plastic fragments, flakes, or beads of size less than 5 mm diameter. Due to the anthropogenic activities, these persist ubiquitously in the environment. The high surface area and functionalized surface due to aging and weathering persuade the sorption of toxic contaminants to the microplastics. The microplastics with the adsorbed chemicals are ingested and accumulated by the terrestrial and aquatic organisms. The ingested microplastics and the adsorbed chemicals cause endocrine disruption, reproductive failure, and other developmental disorders. When humans are exposed to these microplastics through food chain, inhalation, and dermal contact, this exposure can lead to an array of health impacts, including inflammation, genotoxicity, oxidative stress, apoptosis, and necrosis. This chapter highlights the interaction mechanisms of the sorption process between the microplastics and the toxic chemicals, factors influencing the sorption process, and the combined toxic effects of microplastics and their adsorbed chemicals on ecosystem.