Bioremediation and Phytoremediation Technologies in Sustainable Soil Management

Volume 4: Degradation of Pesticides and Polychlorinated Biphenyls

Junaid Ahmad Malik, Megh R. Goyal, Khursheed Ahmad Wani

• Publisher: Apple Academic Press
• Year: 2022
• Print ISBN:
  9781774910382
• eBook ISBN:
  9781000571042
• Topic: Technology & Engineering
• Subtopic: Biology
• Index: Technology & Engineering

This 4-volume set focuses on the use of microbial bioremediation and phytoremediation to clean up pollutants in soil, such as pesticides, petroleum hydrocarbons, metals, and chlorinated solvents, which reduce the soil's fertility and renders it unfit for plant growth. The volumes cover the many diverse eco-friendly microbial bioremediation and phytoremediation techniques for sustainable soil management.

Volume 4: Degradation of Pesticides and Polychlorinated Biphenyls addresses pesticide degradation, PCBs degradation, and genetic interventions. It begins by describing environmental pesticide degradation, mechanisms and sustainability, microbes and microbial enzymes, plant microbe interactions, organophosphorus degradations and endosulfan degradation. It then goes on to discuss PCBs and degradation, cypermethrin, degradation by Phanerochaete chrysosporium, and carvone and surfactants for degradation of PCBs. The book also advocates for genetic systems for degradation of PCBs and pesticides, with discussion of the different advantages and disadvantages for each strategy and the various techniques.

Other volumes in the 4-volume set:
• Volume 1: Fundamental Aspects and Contaminated Sites
• Volume 2: Microbial Approaches and Recent Trends
• Volume 3: Inventive Techniques, Research Methods, and Case Studies

Together, these four volumes provide in-depth coverage of the mechanisms, advantages, and disadvantages of the bioremediation and phytoremediation technologies for safe and sustainable soil management.

PART I Microbial Degradation of Pesticides

CHAPTER 1 ENVIRONMENTAL PESTICIDE DEGRADATION: MECHANISMS AND SUSTAINABILITY

MUZAFAR RIYAZ, PRATHEESH MATHEW, RAUF AHMAD SHAH, K. SIVASANKARAN, and S. M. ZUBER

ABSTRACT

Pesticides are the chemical compounds that are used to control various pests and disease spreading vectors like mosquitoes, ticks, and household pests such as rats and cockroaches. Majority of the pesticides are used in agriculture to control various types of insect pests as well as non-insect pests like ticks and mites, weeds, and fungal infestations and other crop diseases. Pesticides assume a comparative job in saving the crops from notorious pests thereby boosting the economy of a country. However, with the rise in global population, the crops are being cultivated in large-scale resulting in unrestricted utilization of the pesticides. Pesticides have been linked to various environmental contaminations like soil, water, and air. In addition to removing the insects, weeds, vectors, and other household pests, there has been a great impact of pesticide use on the beneficial insects like pollinators, birds, fishes, non-target plants and on the human health as well. Removing pesticides from the environment, abiotic, and biotic transformations play an important role in cleansing the pesticide residues from the environment. Environmental degradation of pesticides involves biotic transformation processes facilitated by microorganisms or plants and by the abiotic processes such as chemical and photochemical reactions.

1.1 INTRODUCTION

From the dawn of ancient agriculture to the modern-day precision farming; our earth has witnessed a number of famines and over millions of people have died due to lack of food triggered either by pest outbreaks, wars, or crop failure. But with the passage of time, mankind has avoided such catastrophes with the development of pesticides back in 1948 [1]. Pesticides are usually man-made chemicals which are used to control pests which include mostly insect pests followed by fungi, viruses, bacteria, weeds, rodents, etc. The range of consumption of these pests may vary as many pests either consume a full crop or a portion of it. Therefore, directly or indirectly, may threaten our food supply. In the present time, our food system is totally dependent on the pesticides, since with the rise in global populations across the planet, food supply is one of the major issues to be taken care of. Although, monoculture (single crop farming) taken care of it, however it also left our crops exposed to extensive attack by the pests which in turn has added more utilization of pesticides in our farm fields [86]. For safeguarding crops, mankind has been in battle with pests since ages, when ancient Sumer used sulfur dusting to save the crops from the pests which date back 4,500 years in Mesopotamia [44]. From the evolution of pesticides to the progression of modern agriculture, the widespread use of pesticides by farmers and the general public has been linked to various environmental contaminations like soil, water, and air. In addition to removing the insects, weeds, vectors, and other household pests, there has been a great impact of pesticide use on the beneficial insects like pollinators, birds, fishes, non-target plants and on the human health as well [158]. While utilizing the pesticides, the residues can remain in the environment for a long period of time and can be dispersed over a long distance. Pesticide residues in soil and water can pose a threat to the biological diversity and human health. After subsiding in the environment, the pesticides start to break down and forms new chemicals that are more or less toxic [29]. To enter into the environment, pesticides are having many possible sources after getting sprayed at large quantities. When exposed to sunlight or microorganisms in soil, most modern pesticides degrade easily however, the utmost number of pesticides after application scatter into non-target areas or leach into groundwater or move in surface run off by misuse and misapplication while handling or spraying. While spraying these chemical pesticides, a series of reactions a pesticide can undergo; plants can take up pesticides through leaves and roots, atmosphere can take up pesticides as vapors, pesticides can get ingested by insects, worms, and microorganisms, carried off as drift (Figure 1.1). In some cases, soil particles are the factors that pesticides can adhere with or rainwater and irrigation can dissolve can provide a quick transportation to carry the pesticides in nearby water streams and rivers which in turn can pose serious threats to our water bodies, aquatic organisms, and environment as well [95, 99, 139].

FIGURE 1.1 After application, pesticides can be taken up by non-target organisms (plants, insects, earthworms, microorganisms).

Source: Photos: Muzafar Riyaz.

Pesticides have improved over time and are currently regulated by the strict safety standards. However, with the large-scale utilization they still hold the potential to contaminate our ecosystems, pollute soil, water, air, impact on wildlife, beneficial pollinators, and human health. There are number of properties that pesticide can establish within the environment that can affect the behavior of a particular ecosystem. The pesticide and its degree of risk to the environment depend upon four factors. Environmental risks of the pesticides can be summarized by analyzing these four factors. These are the properties of pesticides which after application can cause short-term or long-term effects on the environment and other organisms as well by either persisting at a long period or by drifting to places other than target sites [74] (Figure 1.2):

FIGURE 1.2 Factors affecting pesticide and its degree of risk to the environment.

1. Persistence: How long the pesticide remains active in the environment.
2. Mobility: How easily the pesticide can move from where its applied.
3. Non-Target Toxicity: How toxic is the pesticide to other organisms other than pest.
4. Volume of Use: How much of that pesticide is used in the environment.

A number of properties of pesticides can affect their behavior in their environment and can cause a multiple number of environmental contaminations which include persistence, degradation, bio-accumulation, volatility, adsorption, and absorption [143]. Sooner or later, pesticides are broken-down in the environment by a process called degradation. Depending upon the nature of pesticide and environmental conditions of a particular area, the process of degradation can be rapid or deliberate. However, microorganisms present in soil, chemical reactions and sunlight play a key role in the degradation of pesticides. On the other hand, pesticide molecules can be a food source of microbes while taking the advantage of moist and warm soils; microbes can turn the pesticide molecules into carbon dioxide and water. Some pesticides such as chlordane and DDT (dichlorodiphenyltrichloroethane) do not break down quickly; this class of pesticides are called persistent pesticides [56]. Persistence can be greater in heavy clay or organic soil than in sandy soil. Some pesticides after intake through food, water or air may accumulate or build-up in body tissues or body fat of humans and animals by a process called bio-accumulation [196]. If the organism cannot eliminate the p...

Table of contents

• Cover Page
• Half-Title Page
• Title Page
• Copyright Page
• About the Editors
• Table of Contents
• Contributors
• Abbreviations
• Foreword
• Preface
• Part I: Microbial Degradation of Pesticides
• Part II: Polychlorinated Biphenyl (PCBS) Degradation
• Part III: Genetic Intervention
• Index