Living things such as humans, plants and animals can be injured when exposed to high concentrated air pollutants arising Motor Vehicles combustion.

In case of humans and animals it may lead to death and as for crops these can injure the leaves causing stunted growth and reduced yields.

The development and severity of the injury depends not only on the concentration of the particular pollutant but also on a number of other factors.

These include the length of exposure to the pollutant, the living things are exposed to and its stage of development as well as the environmental factors conducive to a build-up of the pollutant and to the preconditioning  these categories, which makes them either susceptible or resistant to injury.

Common pollutants

Some of these pollutants may directly affect the soil leading to infertile and acidic soil content, if used for farming will lead to low yields.

As for case of humans these pollutants from motor vehicles which are road safety issue where in some cases there are spill over of fluids will directly affect human health

Most common pollutants, which end up affecting agricultural activity and human life in most cases from Motor vehicles and other sources include sulphur dioxide, fluorides, ammonia, chlorine and particulate matter.

But experts say widespread pollutants consist primarily of oxidants. Ozone, the major component of oxidants, is produced in the atmosphere during a complex reaction involving nitrogen oxides and reactive hydrocarbons, components of automobile exhausts and fossil fuel burning mainly from old Motor vehicle stuck in jams.

As this process proceeds only in sunlight, it is called a photo-chemical reaction leading to injury on living things.

Deadly mix

Air pollution injury to plants and humans can be evident in several ways. In the case of plants injury to the greenery of the leaf may be visible in a short time and appear as dead tissue, or it can develop slowly as a yellowing of the leaf.

There may be a reduction in growth of various portions of a plant. Plants may be killed outright, but they usually do not succumb until they have suffered recurrent injury.

As for the case of humans and animals, it may affect the lungs leading to developing diseases such as Tuberculosis.

Prof Shem Wandiga, from University of Nairobi, while explaining the dangers of air pollution to agriculture and humans pointed out that photo chemical smog, a chemical reaction of sunlight, nitrogen oxide and volatile organic compounds in the atmosphere increases with the amount of sunshine.

In the end, it is dangerous to plants, animal and human beings.

This was during a zoom meeting about Air pollution on human health and plants arising combustion from Motor Vehicles and other related chemicals.

In the case of Agriculture besides chemicals farmers use such as herbicides, fertilizer, dichloro-diphenyl-trichloro-ethane (DDT) and others end up having negative effects on the soil leading to polluted soil with no soil fertility.

According to Prof Wandiga, considering how soil is the reason we are to sustain agriculture for our livelihoods, the contamination of it has major effects on our health because crops grown on polluted soil absorb much of the pollution. This is passed to humans and animals which feed on it.

Unable to adopt

The ecological balance of any system gets affected due to the widespread contamination of soil.

Most plants are unable to adopt when the composition of soil changes because fungi and bacteria found in soil that bind it together begin to decline which ends up creating another challenge of soil erosion.

The fertility diminishes making land unusable for agriculture and any vegetation to survive.

He noted that emissions from motor vehicles via diesel and petrol use as one of the dangerous pollutant, which may end up accumulating on soils making it become infertile.

Air pollution from gases such as sulphur dixide are acidic in nature and become corrosive in the atmosphere. Once they drop on the soil, it also becomes acidic rendering the soil infertile for any agricultural activity.

Major sources are coal-burning operations, especially those providing electric power and space heating.

Sulphur dioxide emissions also come from the burning of petroleum, diesel and the smelting of Sulphur containing ores.

Other disastrous gases to plants and humans are fluorides, which are discharged into the atmosphere from the combustion of coal, the production of brick, tile, enamel frit, ceramics, and glass, the manufacture of aluminium and the production of hydrofluoric acid, phosphate chemicals and fertilizers.

Fluorides absorbed by leaves are conducted towards the margins of broad leaves of crops and to the tips of monocotyledonous leaves.

Mix of gases

Little injury takes place at the site of absorption, whereas the margins or the tips of the leaves build up injurious concentrations.

Since plants have breathing system called stomata, the breathing hole will end up being clogged leading to the plants to get withered.

Once there is air pollution in the atmosphere, these will lead to gases such as methane, carbon dioxide and oxygen to get mixed up thereby changing the temperature.

This causes changes in the rainfall partners thereby affecting farming system because farmers will not be sure as to when to plant their crops as a result of the changes.

Usually such gas mixtures are worsened with pollutions from Motor vehicles especially in cities which is a road safety issue.

Dr Kawuki Kayizzi, from the National Agricultural Research Laboratories (NARL) Kawanda in Uganda explains that air pollution arising from gas emissions and dust is a challenge for agricultural land. And human health.

He said many farmers do not realize it because they don’t pay attention to it but farmlands which are close to industries and cities where there is existence of old motor vehicles are more affected.

Dust blown from such places as those from Sahara desert come with chemical particles of Sulphur dioxide, which is eventually combated to acidic rays.

Once it accumulates on soil it renders it infertile for any farming activity but farmers will not realize this.

Instead they will go ahead to plant crops leading to poor yields and humans will contract none communicable diseases if not treated will lead to death.

If such dust settles on soil, during rainy season it will be washed into water bodies thereby ending up destroying fish species.

Sometimes air contamination in the atmosphere ends up polluting the clouds which end up in acidic rain thereby causing destruction to plants and humans as a result of absorption.

Statistical figures

UN Economic Commission for Africa estimates the cost of air pollution in African cities can be as high as 2.7 per cent of the country’s Gross Domestic Product.

In Kenya, 40 per cent of air pollution is caused by vehicles while the estimate for Nigeria is 43 per cent.

East African countries have moved to reduce the Sulphur content in diesel to curb this danger.

It is recommended that countries should set standards for monitoring air quality alongside other solutions such as afforestation and zonal planning.