How Fruit Absorbs Pollution: A Health Risk?

With increasing awareness about the environment and public health, many people are taking up gardening and planting their own fruits and vegetables. However, concerns have been raised about the potential impact of pollution on the safety of consuming these fruits and vegetables. While carbon dioxide and nitrous oxide emissions from vehicles do not threaten plants, pollutants from human activities, such as agriculture, industry, and urban life, can increase harmful heavy metals in the soil, which can be absorbed by fruits and vegetables. Researchers have found that, in most cases, consuming fruits and vegetables grown in contaminated soils is safe, but thorough washing is essential to reducing the risk of ingesting soil particles.

Plants near busy roads absorb carbon dioxide and nitrous oxides

Plants absorb carbon dioxide and nitrous oxides, which are two of the three main types of pollution produced by cars, the third being particulates. Carbon dioxide is used by plants for photosynthesis, the process by which they synthesize their food. Therefore, carbon dioxide emitted by vehicles does not threaten plants. Nitrous oxides also do not pose any risk to plants as nitrogen binds to the soil and acts as a fertilizer.

However, plants near busy roads are at risk of contamination by other compounds in vehicle exhaust, such as oxides of sulfur and nitrogen, which contribute to acid rain. Acid rain lowers soil pH, interfering with nutrient uptake and potentially causing direct damage to plants. Additionally, particulate matter from vehicles, including complex hydrocarbons and heavy metals, can mix with dust and settle on nearby vegetation, reducing the amount of sunlight the plants receive.

The risk of plant contamination generally increases with proximity to busy roads. Therefore, it is recommended to research the soil and surrounding area before starting an at-home vegetable garden near a busy road. While plants near busy roads can absorb carbon dioxide and nitrous oxides without harm, other pollutants may pose a risk to their health and the health of those consuming edible plants grown in these areas.

Pollution risk increases with proximity to busy roads

The pollution risk from traffic-related air pollution increases with proximity to busy roads. This is a major public health concern, particularly for children, and can also affect fruit and vegetable plants grown in these areas. Motor vehicles are a significant source of urban air pollution, releasing carbon dioxide and nitrous oxides, which form smog in urban areas and are harmful to humans.

Health Risks

Studies have found evidence of increased health risks linked to proximity to busy roads. These include respiratory health issues, allergic diseases, and cardiovascular problems such as impaired lung function and increased risk of ischaemic heart disease. Living close to busy roads can also expose individuals to noise, odours from fumes, and dust, which can decrease the quality of life.

Plant Contamination

Plants located near busy roads can absorb pollution and become contaminated, although it depends on the type of pollution and the distance from the road. Carbon dioxide, a common air pollutant from vehicles, is not harmful to plants as they use it for photosynthesis. However, other pollutants such as nitrous oxides, ultrafine particles, carbon monoxide, NO2, black carbon, and polycyclic aromatic hydrocarbons can contaminate plants and the soil they grow in.

Reducing Risks

To reduce the risk of consuming contaminated fruits and vegetables, it is recommended to test the soil and research the surrounding area before planting. Thoroughly washing produce with water can also help remove soil particles and decrease the chance of consuming contaminants. While the risks associated with gardening in polluted areas may be lower than previously thought, it is important to take precautions to ensure the safety of the produce and the health of those consuming it.

Vegetables absorb heavy metals from soil and polluted air

Vegetables can absorb heavy metals from soil and polluted air, and this has been the subject of numerous studies. Heavy metal contamination in vegetables is a severe concern as it can have detrimental impacts on food sustainability and human health. The accumulation of heavy metals in vegetables can result in various ailments in consumers, including cardiovascular, neurological, renal, and bone illnesses.

The sources of heavy metals in soils are varied and include natural sources such as soil parent material, volcanic eruptions, marine aerosols, and forest fires. Agricultural practices, such as the use of fertilizers, sewage sludges, pesticides, and irrigation water, can also contribute to metal contamination in soils. Energy and fuel production, mining and smelting, automobiles, and urban/industrial complexes are other significant sources of heavy metals in the environment.

Vegetables grown in areas polluted with heavy metals or near sources of heavy metal pollution may accumulate higher amounts of these toxins. The roots of plants absorb heavy metals from the soil, and these toxins can enter the edible sections of plant tissues or accumulate on the surface of vegetables. The sensitivity, supplementation, potential dangers, and sources of heavy metals in soil-grown vegetables have been reviewed in studies.

The health risks associated with consuming vegetables contaminated with heavy metals have been assessed using the Target Hazard Quotient (THQ) method. This method considers factors such as the intake of pollutants, exposure time, body weight, and reference oral dose of pollutants. Studies have found clear differences in the concentrations of heavy metals in the edible parts of different vegetables, with leafy vegetables absorbing and accumulating higher levels of heavy metals compared to other types.

While the proximity of soils to pollution and industry can increase the levels of contamination, some scientists have found that the risks associated with gardening in these soils may be lower than initially thought. For example, researchers at Kansas State University found that, in most cases, eating vegetables grown in contaminated soils was safe. They grew tomatoes, collard greens, and carrots in soils contaminated with lead, arsenic, and polycyclic aromatic hydrocarbons, and found that the vegetables had low levels of all the contaminants.

Soil testing and washing produce reduce health risks

Plants near busy roads can absorb pollution and become harmful, depending on the type of pollution and proximity to the road. Carbon dioxide and nitrous oxides are common air pollutants near busy streets, but plants use carbon dioxide for photosynthesis, and nitrogen has a fertilizing effect on plants. Nevertheless, it is important to test the soil for contaminants before planting and consuming vegetables and fruits.

Soil health testing provides useful information about specific soil functions to farmers, landowners, agronomists, and crop consultants. It is an indicator of broader functions occurring within the soil, such as aggregation, structure, water infiltration rate, storage capacity, biodiversity, and nutrient cycling ability. Soil health tests can help identify potential risks based on site characteristics and determine practices to improve soil health and function. For example, reducing tillage, incorporating cover crops, or adding a small grain to the crop rotation can improve soil health.

Before starting an at-home vegetable garden, it is essential to conduct intensive research on the soil and surrounding areas. Soil testing can identify contaminants such as pesticides, heavy metals, and PFAS. Total lead analysis should be conducted rather than correlation lead analysis to ensure accurate results. By testing the soil, individuals can make informed decisions about the safety of consuming produce grown in that soil.

Washing produce is another crucial step in reducing health risks. Food safety experts recommend rinsing, scrubbing, and drying fruits and vegetables before consumption. This practice helps remove dirt, sand, small insects, and pesticide and herbicide residues that can pose health risks to the nervous and endocrine systems. While organic produce is generally considered safer, it is still important to wash it thoroughly.

Additionally, specific produce requires more thorough washing. Leafy greens such as spinach, lettuce, and kale can harbor dirt, bacteria, and residues in their many layers. Strawberries, blueberries, and raspberries often hide dirt and pesticide residues. Raw sprouts like alfalfa and bean sprouts can carry pathogens like salmonella and E. coli, so thorough rinsing or cooking is recommended for high-risk individuals. A food scientist also suggests briefly submerging berries in a diluted vinegar and water solution to remove dirt, bacteria, and pesticide traces.

Urban gardens have health and environmental benefits

Urban gardens have a plethora of health and environmental benefits. They are a great way to promote healthy eating, as they provide access to fresh fruits and vegetables. A study found that people who planted in community gardens ate their daily recommended amount of fruits and vegetables at more than twice the rate of people who didn't garden. Moreover, urban gardens can also help reduce household concerns about food security.

Urban gardens can also be beneficial for physical and mental health. They provide a space for people to connect with nature, relieve stress, improve physical health, and enhance overall well-being. Research has shown that children who are disconnected from nature are more likely to face health issues such as obesity and attention disorders. Urban gardens provide a space for children to play, learn about food production, and develop social skills.

In addition to the health benefits, urban gardens also have environmental advantages. They can help reduce the urban heat island effect, which is caused by the concentration of buildings and impervious surfaces in cities that consume and reflect more heat. The urban heat island effect can worsen respiratory problems and heat-related illnesses, especially in vulnerable communities. By planting trees and other vegetation, urban gardens can help cool the environment through evapotranspiration and provide shade to reduce heat absorption.

Furthermore, urban gardens can help improve air quality by reducing carbon in the atmosphere and providing a healthy habitat for pollinators, birds, and other wildlife. They also offer hands-on opportunities for people to learn about ecological processes and inspire them to make environmentally conscious choices in their daily lives.

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