Impact of Farming on PM 2.5 Air Pollution & How to Mitigate it

 What is PM 2.5 and Why is it Harmful?

Particulate matter with a diameter less than 2.5 micrometers (PM) is termed PM 2.5. These particles come in different shapes and designs and comprise a mixture of wide range of components including but not limited to acids, organic chemicals, metals, or soil or dust particles. Being extremely small in diameter, PM 2.5 Air Pollution can be inhaled and absorbed into the bloodstream and this causes a pain of some kind.

Negative health effects induced by exposure to PM 2.5 are:

• Respiratory disease such as asthma and reducing lung asthma and bronchitis function
• Risk of cardiovascular disease, stroke and sudden death
• Existing heart and lung disease are worsened
• Adverse effects on pregnancy and later involve in childhood health problems

Inhalation of PM 2.5 is viewed as being more dangerous than inhalation of other bigger particles because PM 2.5 manages to penetrate into the deep lungs and lasts longer in the air. Such exposures, however low they may be, without fail there is a plight facing public health institutions.

Existing Agricultural Methods Increasing PM 2.5 Air Pollution

It has been established that agricultural activities contribute significantly to PM emissions including PM 2.5 which are defined as inhalable particles including those with diameters of 2.5 micrometers or less. Such particles are exhaustively small in nature and can easily be inhaled into the alveolar regions of the lungs provoking health complications among the exposed individuals. There are also other processes that are in agricultural practices that increases concentration of PM 2.5 in the atmosphere.

Tillage and land preparation methods: Adoption of conventional tillage processes which involves activities such as ploughing and disking will often involve disturbance of the soil surface which leads to emission of a lot of dust and particulate matter. Such particles are known to take long periods before settling down and thus lead to increase PM 2.5 concentration in the area.

Burning of crop residues: Such practice is rampant in several countries whereby, after harvesting wheat and rice, farmers will burn the crop stalks off the fields in a bid to prepare the land for the coming planting season. Such open burning also causes disturbing amounts of PM 2.5 to be released into the atmosphere and other toxic gases such as carbon monoxide, nitrogen oxides as well as volatile organic compounds.

Livestock Operations: Concentrated animal feeding operations (CAFOs) and other livestock facilities have the potential to produce a lot of PM 2.5 due to practices carried out in such facilities, such as feed and food particles handling, movement of animals and handling of manure. Particulate matter from these sources contributes to the unhealthiness of the air in areas near these parameters.

Fertilizer Application: The introduction of certain categories of fertilizers, especially those that include nitrogen in form of ammonia, can eventually lead to the production of fine particulate matter as a result of some reactions with the atmosphere. In addition, dry fertilizers may lead to dust and subsequent PM 2.5 Air Pollution emissions while being spread and handled.

Regions with High Agricultural PM2.5 Emissions

Agricultural processes, but especially livestock production and crop growing, are not uncommon in some regions as practices which introduce PM2.5 into the air. Such emissions are associated with a number of activities including livestock housing, manure application, burning of crowns of residual crops, and cultivation tillage and harvesting operations.

One more striking example of such area, with increased PM2.5 emission from agricultural activities, is the Central Valley of California. This area, known for its fertile soils, is the location for many dairy factories, cattle feed farms and cropped lands. This process of intensive active cattle keeping and tillage creates an atmosphere, where air pollution is increased as a result of particulate matter in the atmosphere.

Another region with relatively high agricultural PM2.5 emissions is the Midwest United States especially such states as Iowa, Illinois, Minnesota. These are the “Corn Belt” states which are vital for production of corn and soybean and other crops, and associated farming activities like tillage and harvesting also have considerable levels of particulate matter generation.

In Europe agricultural regions include Po Valley, Italy and Ebro Valley in Spain with agricultural intensive practices and commensurate PM2.5 emissions. Po Valley is considered as one of the major agricultural producers of livestock and crops. In addition, the emissions from these activities together with the geological and meteorological characteristics of the region promote the plumes of particulate pollution.

In some parts of Asia too, for instance, the Indo-Gangetic Plain in India and Pakistan enhanced levels of agricultural PM2.5 emissions were recorded. This region is notorious for its crop burning upon harvesting, which is rampant, thus posing a great threat to the ambient air quality.

Source: FAO

Seasonal Changes in Agricultural PM 2.5 Air Pollution Sources

PM2.5 emissions due to agricultural activities do not remain constant through-out the year. Such degree of violence in temporal pattern is guided by such factors as cropping system, cattle management systems and climatic attributes.

In most locations, a number of agriculturally driven PM2.5 emissions appear to be more concentrated or pronounced at certain times of the year. For example, spring tillage and planting practices can cause soil activity that drives airborne dust production, thus raising the level of PM2.5 pollution. Just as in spring, there are also chances that fall harvesting activities may raise PM2.5 levels as well due to the disturbance of crops and dust emissions from the plant materials.

Weather conditions are important for the varying patterns of PM2.5 emissions from agriculture over the year. A long and strong summer drought can lead to additional outward dispersion of particles which escaped from agricultural activities which tillage, and livestock operations, as well as crop residue burning. Tillage operations may produce PM2.5 dusts but in the following rainfall season, slash-and-burn practices may cause PM2.5 particles bound to soils or vegetation and hence cannot be easily removed.

Moreover, certain types of agricultural practices such as open burning of crop residues are usually spaced out such that their occurrence in a particular place does not lead to continuous raising of PM2.5 emissions. On the other hand, agricultural applications, such as concentrated feeding operations (CAFOs), as well as others, are characterized by seasonal variations of PM2.5 emissions due to the housing of animals, feeding, manure management and other activities that change with time.

Grasping these features of the pasterns and their determinants is crucial in design of approaches which will actively aid in reducing the overall agricultural PM 2.5 Air Pollution that can endanger the health of the populace and their environment.

The role played by agriculture and other practices in the emission of particulate matter (PM) 2.5 which has been shown to have a grave impact on air pollution and human health. PM 2.5 is a term used to refer to particles or droplets that are less than or equal to 2.5 micrometers in diameter and can be inhaled. These fine particles are small enough to passed through the trachea and end up in the blood system causing a number of disorders in the lungs or other vascular systems as a result of embolism. 

It is observed PM 2.5 production is high through and when agricultural related activities such as farming, tilling, harvesting, livestock operations or animal husbandry, and others are in progress. Major sources of these fine particles are agricultural equipment, the incendiary use of agricultural residues, and pulling feed and animal dwelling dusts. In addition, the usage of fertilizers and pesticides would lead to generation of secondary PM 2.5 due to redistribution and chemical reactions that take place in the air.

The extent to which PM 2.5 from agriculture contributes to the overall air pollution potential is contingent on geographical as well as farming practice. In case of rural communities and farming regions with high farming activities, this is the case. In such areas, the variations are already present, and air pollution impacts can be severe. Although PM 2.5 from agricultural activities may be locally generated, they are susceptible to long-range transport and hence further increase the prevalence of ambient air pollution beyond the immediate area.

Exposure to relatively high levels might result in numerous health impacts and diseases such as asthma and COPD, heart diseases and ultimately result in increased mortality. Explaining the reasons behind this, the risk of negative health effects of PM 2.5 pollution is substantially greater among women, children, elderly and individuals suffering from respiratory or cardiovascular diseases.

In fact, it has been shown that addressing agricultural PM 2.5 emissions can lead to improvements in air quality and health outcomes. The introduction of sound agricultural technologies which include conservation tillage farming, precision farming and improved manure management systems have been suggested as ways of reducing PM 2.5 from agricultural practices. Moreover, the adoption of more efficient and less polluting agricultural equipment, and the implementation of alternative strategies to manage crop remains could also lessen the influence of agricultural PM 2.5 on air quality.

Assessment and Mapping of Agricultural PM 2.5 Emissions

In order to appreciate the contribution of agriculture to air pollution and develop counteracting measures, it is important to assess the PM 2.5 emissions from agriculture activities. There are several methodologies and techniques, which are used to determine and evaluate PM 2.5 emissions from agricultural sources.

The traditional land-based monitoring system is one such method that is commonly used. The techniques employed for this purpose include particulate matter monitors, air samplying devices etc. These monitoring stations are installed in agricultural areas in order to measure PM 2.5 levels and their constituents on a regular basis. Such monitoring is beneficial in monitoring patterns, seasons and locations of emissions.

Another emerging strategy is the use of PM25 satellite remote sensing for PM2.5 measurement over large areas. Such sensors examine aerosol optical depth, which can be related to PM2.5 levels over very large agricultural areas. This method is more effective as it covers wider area and helps in monitoring the movement of air borne dust.

Alongside direct measurements, agricultural PM 2.5 emission measurements are also carried out using computer models and simulations. These models require various input parameters including agricultural practices, crops grown, soil type, meteorological data, and emission factor. By changing and testing their parameters, these models help to establish how farming practices contribute to PM 2.5 levels and how these levels of pollution can be controlled.

However sophisticated measuring methods get developed; some gaps still exist with regards to agricultural PM 2.5 emission estimates. One of the main limitations is that the very challenges or agricultural activities that need to be measured are highly complex within agriculture, including tillage, harvest of crops, livestock activities, and burning of agricultural waste. PM 2.5 emissions can be associated with either of these activities but distinguishing between them and measuring emissions becomes a challenge.

Emission factors, on the other hand, may also vary as a result of soil type, type of crop, weather conditions, and management practices. Accurate and site-specific emission factors are important to make reliable newspaper emission estimates.

Furthermore, the monitoring and effect quantification are made more complex by the spatial and temporal diversity of agricultural activities. Agricultural operations are often widely dispersed over a surface and change across the seasons, hence it is often impossible to monitor their emissions due to all the limitations related with it. In order to improve emission inventories and monitoring techniques, several other scientists are engaged in processes which in one way or the other contribute to this goal. For example, vertical farming techniques improve the collection of agricultural PM 2.5 emissions by conducting translational modelling and integrating remote sensing data with in-situ measurements. Also, technological development of sensors, data processing, and computer capacity facilitates the monitoring and modelling processes more effectively and at a higher resolution.

Strategies and Best Practices to Reduce Agricultural PM 2.5 Emissions

It is important to tackle the PM 2.5 emissions from agricultural activities in order to improve the quality of atmosphere and protect the health of people. Achieving such a goal is viable through several strategies and best practices:

Sustainable Farming Methods to mitigate PM 2.5 Air Pollution:

• Conservation Tillage: Use of conservation tillage practices such as no or minimum tillage can reduce soil overturning and minimize particulate emissions into the atmosphere. These methods ensure that soils are not exposed to wind and water erosion thus lowering emissions of PM 2.5.
• Cover Crops: The sowing of cover crops in fallow land is an undertaking that aims to protect the soil from erosion and the release of PM 2.5. Cover crops are integrated into the soil for soil stabilization, reduction of wind erosion, and soil security enhancement.
• Precision Agriculture: The application of various techniques of precision agriculture such as variable rate technology or adjusting for site-specific nutrient applications can assist in fertilizer use efficiency and minimize chances of PM 2.5 pollution from fertilizer overuse.
• Integrated Pest Management: Employing integrated pest management (IPM) practices as part of strategies can reduce how often pesticides will apply, which is a source of PM 2.5 emissions by way of drift and volatilization.

Policy Interventions:

• Emission Standards and Regulations: Setting and implementing required emission standards for structures and activities like livestock, crop burning, and machinery usage in the farm can aid in controlling PM 2.5 emissions.
• Incentives and Subsidies: Farmers who engage in sustainable agricultural practices and emission reductions can be offered incentives and subsidies in order to promote the adaptations and compliance to such activities.
• Public Awareness and Education: Awareness can be raised among farmers and general public as to the PM 2.5 emissions effects as well as best practices so as to increase environmental sensibility and responsible agricultural practices.
• Research and Development: It is paramount to allocate resources towards research and development in order to discover new technologies, improved farming systems or emission reduction measures to help in lessening the PM 2.5 emissions from agriculture.

Managing these impacts does require the implementation of certain combinations of sustainable farming methods as well as the adoption of various policy interventions. In so doing, adopting these strategies and best practices transforms the agricultural industry into a better and safer industry for the welfare of the citizens and the environment.

Effective Case Experiences in the Control of PM 2.5 from Agriculture

There are many areas and countries that have implemented successful pollution controls of agricultural PM 2.5 emissions, noting the capacity for improvement. One such important example is San Joaquin Valley in California, which has seen a great improvement in air quality owing to cooperation between farmers, regulatory authorities and researchers.

And thanks to the enactment of strict laws, the practice of conservation tillage, and the use of control measures for particulate matter such as air filtration systems and sprinklers, there has been a powerful lowering of PM 2.5 concentration levels in the area. Furthermore, the promotion of more sustainable agricultural practices such as precision agriculture and integrated pest management helped in emissions reductions from agricultural activities too.

By adopting a similar approach, it has been possible to achieve some success in Denmark, with a complete national action plan formulated focusing on agricultural emissions. The government of Denmark has taken action, such as providing funds to farmers who adopt low-emission techniques and imposing strict limits on the amount of manure a farmer can spread on land. These activities have achieved not only PM 2.5 reduction but also led to better quality of air and soil in the regions.

In China, where such agricultural activity contributes significantly to air pollution, certain technology and policy measures have had a positive impact. One of the steps that the state has taken was to ban such practices as open burning of residual agricultural materials, which is a significant contributor to PM 2.5 pollution. Such practices as mechanized harvesting have also been encouraged and having agricultural remains put into good use, for instance, in biofuel production has also reduced emissions.

The achievement in these regions and countries, can largely be attributed to the following main factors: strong political will, effective coordination of relevant players and stakeholders, funding of research and development and embracing of environmentally favorable farming systems. These case studies, however, show how the sources of PM 2.5 emissions from agriculture can be reduced with a minimum negative impact on agricultural output, and consequently how such interventions can benefit the air quality.

What Constrains on Reducing Agricultural PM2.5 Emissions

There are, however, other specific issues that make the problem of PM2.5 emissions from agricultural activities a serious challenge that needs to be addressed. These challenges are economic development, social impact and technology development, making the mitigation challenge complex and multidimensional.

Many agricultural activities that lead to PM 2.5 emissions, from the economic perspective, are how people have farmed over the years hence they are a part of the norm in most regions and they are created out of cost-effectiveness and profitability. This is not to say that there are no institutions that promote the transition to alternative /environmentally friendly agricultural practices. Switching to better practices is costly and electronics however often substantial initial cost on new equipment, training, and facilities. Farmers in developing countries or those who farm on a small scale are likely to be economically disadvantaged and therefore may not have the capacity to employ cleaner technologies or practices.

Social and cultural factors also impact the challenges faced in implementing measures towards reduction of agricultural PM2.5 emissions. For example, some agricultural practices like open burning of crop residues may be part of the local practices, therefore making it hard to alter such practices and attitudes. Also, EF of PM2.5 emissions, related to a particular practice, may be low due to unawareness or lack of wants for the sustainable alternatives to be embraced.

Furthermore, there are also technological barriers towards PM2.5 emissions improvements within the agricultural sector. In some areas, including Northern Uganda, there are limitations towards the use of new low emissions agricultural practices and machinery due to the governments policies and cultures. Moreover, the successful research, development and adoption of new technologies such as precision agriculture or emissions capture technologies is a demanding activity in terms of funding, as well as opportunities for knowledge transfer and capacity building.

In order to cope with these concerns, it is essential to develop a strategy that takes in consideration economic benefits, social dimensions and technology components. For example, financial support measures such as subsidies or special tax conditions might seek to convince agriculturalists to clean up their operations. Public outreach and community safe issues initiatives will assist in changing the change in attitudes of people and increase comprehension in relation to atmospheric PM2.5 intolerance. Moreover, such knowledge and technology transfer programmes coupled with increasing support for research are necessary to accommodate the localizations of these novel solutions.

Lessening Agricultural Based PM 2.5 Emissions: A Future Prospect

With more and more attention being placed on air quality and its deleterious effects on public health and the environment, it becomes more and more relevant to look at the share of the agricultural sector in ‘agricultural’ PM 2.5 emissions. Unsurprisingly, farming activities have traditionally been responsible for producing these fine particles. But new trends and innovations might be useful in minimizing agricultural PM 2.5 emissions.

One of the most useful of these can be said to be the application of precision farming practices. Thanks to the application of data science and the necessary technologies, the agricultural sector has changed in a way that it cut down on common expenses like unnecessary land preparation, generation of dust and even improve the soil. The same holds for fertilizers and pesticides, where precision agriculture allows application in ways that achieve the best outcome with reduced chances of PM 2.5 infestation.

A more in a similar way is a developing trend as regards agricultural activities. Regenerative agriculture methods improve the health of soils, water efficiency and the level of biological diversity, often through practices such as the use of cover crops, crop rotation and conservation tillage. Healthy and well-structured soils are created which do not allow air pollution through soil erosion thus regenerative agriculture can prevent air pollution that is a result of PM 2.5 particulate matters.

Also, the design of farming equipment that produce lower PM 2.5 emission is also a step in the right direction. Trying to create engines with these values as the current diesel powered machines are being manufactured for efficient usage.