Air pollution significantly reduces chlorophyll content, with far-reaching implications for plant health and ecosystem productivity. Strategies such as reducing emissions, selecting pollution-tolerant species, and implementing green belts can mitigate these effects. Future research should focus on adaptive mechanisms in plants and long-term ecological impacts.

New Delhi (ABC Live): Air pollution poses a significant threat to plant health, primarily by affecting the chlorophyll content of leaves, which is crucial for photosynthesis.

This ABC Research investigates the effects of key air pollutants such as sulphur dioxide (SO₂), nitrogen oxides (NOₓ), ozone (O₃), particulate matter (PM), and heavy metals on chlorophyll content in plants. Data were collected from four case studies involving urban trees, agricultural crops, industrial regions, and roadside vegetation. Results reveal a consistent reduction in chlorophyll content under polluted conditions, with the degree of impact varying by pollutant type and exposure levels.

This ABC research highlights the need for mitigation measures and further exploration of pollution-tolerant plant species.

Introduction

Chlorophyll, the green pigment in plants, plays a pivotal role in photosynthesis. Air pollution disrupts chlorophyll biosynthesis and accelerates degradation, leading to reduced photosynthetic efficiency and plant productivity. This study aims to provide a comparative analysis of the effects of different air pollutants on chlorophyll content, drawing insights from field studies and experimental setups.

Materials and Methods

1. Study Design

Four distinct case studies were analysed to evaluate the impact of air pollution on chlorophyll content:

• Urban trees exposed to SO₂ and NOₓ in Delhi, India.
• Agricultural crops subjected to ozone exposure in Illinois, USA.
• Trees near industrial zones with heavy metal pollution in Hunan, China.
• Roadside vegetation affected by particulate matter in Poland.

2. Chlorophyll Analysis

Chlorophyll content was measured using spectrophotometric methods. Leaf samples were homogenized in acetone (80%) and absorbance values were recorded at 645 nm and 663 nm. Arnon’s formula was employed to calculate chlorophyll-a, chlorophyll-b, and total chlorophyll content.

3. Pollutant Measurement

Ambient air quality data were collected using standard monitoring devices. Heavy metals were quantified using Inductively Coupled Plasma Mass Spectrometry (ICP-MS).

Results

Case Study 1: Urban Trees (Delhi, India)

SO₂ and NOₓ exposure led to a 30% reduction in chlorophyll content in urban trees compared to peri-urban trees.

Case Study 2: Ozone (Illinois, USA)

Ozone exposure caused a 31% reduction in total chlorophyll content, correlating with a 20?crease in crop yield.

Case Study 3: Heavy Metals (Hunan, China)

Lead and cadmium accumulation in leaves resulted in a 45?crease in chlorophyll content.

Case Study 4: Particulate Matter (Poland)

Particulate matter reduced chlorophyll content by 29%, primarily due to physical deposition on leaves and reduced light absorption.

Discussion

The findings demonstrate that air pollution negatively impacts chlorophyll content across diverse environments and pollutants. SO₂ and NOₓ hinder chlorophyll biosynthesis, ozone induces oxidative stress leading to degradation, and heavy metals disrupt chlorophyll-protein complexes. Particulate matter impairs photosynthesis by obstructing light penetration and facilitating chlorophyll degradation.

Impact on Human Life

Low chlorophyll content in leaves directly affects human life by disrupting ecosystem services provided by plants. Key impacts include:

• Reduced Air Purification: Plants with lower chlorophyll content have diminished photosynthetic activity, leading to reduced absorption of carbon dioxide and production of oxygen, which exacerbates urban air quality issues.
• Decline in Agricultural Productivity: Ozone and other pollutants reduce chlorophyll in crops, leading to lower yields and food scarcity, particularly in regions dependent on agriculture.
• Ecosystem Imbalance: Decreased chlorophyll impacts plant health, reducing their ability to support biodiversity, including pollinators and herbivores, which are essential for food chains.
• Human Health Risks: Lower productivity of trees and vegetation can contribute to urban heat islands, increase exposure to pollutants, and reduce mental health benefits associated with green spaces.

Conclusion

Air pollution significantly reduces chlorophyll content, with far-reaching implications for plant health and ecosystem productivity. Strategies such as reducing emissions, selecting pollution-tolerant species, and implementing green belts can mitigate these effects. Future research should focus on adaptive mechanisms in plants and long-term ecological impacts.

References

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2. Fiscus, E. L., Booker, F. L., & Burkey, K. O. (2005). "Crop responses to ozone: Uptake, modes of action, carbon assimilation, and partitioning." Plant, Cell & Environment, 28(8), 997–1011.
3. He, Z. L., Yang, X. E., & Stoffella, P. J. (2005). "Trace elements in agroecosystems and impacts on the environment." Journal of Trace Elements in Medicine and Biology, 19(2-3), 125–140.
4. Tomašević, M., & Aničić, M. (2010). "Trace element content in urban tree leaves and PM deposition on leaf surface." Environmental Pollution, 157(1), 215–222.