Table 1: Proximate composition of Manihot esculenta leaves, A                           22

Table 2: Proximate composition of Manihot esculenta leaves, B                           23


In most developing countries, the inappropriate cultivation of edible plants at roadside is neglected. Automobile pollutants, such as particulate matter and heavy metals are toxic chemicals that affect plants and subsequently humans and animals. Manihot esculenta is a popular shrub grown mostly on roadside. Results of comparative proximate analysis carried out on the leaves of manihot esculenta, showed decrease in protein content, 2.188 %, fiber content 2.400%, lipid content 1.113%, moisture content 52.400%, compared to control samples of 5.075%, 4.540%, 1.769%, and 67.997% respectively, and however an increase in percentage ash content 9.767% of the leaves of the plant highly exposed to pollution from automobiles, compared to control with ash content of 6.418%. Therefore growing of plants close to road should be restricted.





Anthropogenic activities tied to industrialization are the major threat to the environment and pollution is just one example. Air pollution is a major problem in the modern society. Air pollution is caused by fumes and smoke from vehicles, factory chimneys and power stations, these substances comprises various gases and tiny particles or particles that harm plants, animals, human health and damage the environment, with burning fuels contributing hugely(Rahul and Kumar, 2014). Particulate matter is the term for particles found in the air including dust, soot, dirt, smoke and liquid droplets. The effect of these pollutants is more localized near roads, quarries, cement works and other industrial areas. The discharge of soot and smoke from automobiles affect leaves of plants that are close to roads. These particulate matter causes stomatal closure of the leaves, curtails photosynthesis, interferes with plant metabolism, subsequently reduces total nutritional value of the plant, impairs plant growth and finally kills the plant. They also result in the toxicity of the plant due to the accumulation of various metals and gases on the parts of the plant.

Plants and vegetables are rich sources of vitamins, minerals, and fibers, and also have beneficial anti-oxidative effects. However, there is a decrease in the amount of nutrients supplied to the body when humans ingest pollutant affected foodstuffs. Intake of heavy metal-contaminated vegetables and foodstuffs may pose a risk to the human health, this is because heavy metals have the ability to accumulate in living organisms and at elevated levels can be toxic. It has been reported that prolonged consumption of unsafe concentrations of heavy metals through foodstuffs may lead to the chronic accumulation of the metals in the kidney and liver of humans causing disruption of numerous biochemical processes, leading to cardiovascular, nervous, kidney and bone diseases (Jarup, 2003).

The Manihot esculenta, commonly called cassava, is a woody shrub native to South America of the spurge family, Euphorbiaceae. It is extensively cultivated as an annual crop in tropical and subtropical regions for its edible starchy tuberous root, a major source of carbohydrates. It is called yuca in Spanish and in the United States. Cassava is the third-largest source of food carbohydrates in the tropics, after rice and maize. Cassava is a major staple food in the developing world, providing a basic diet for over half a billion people (Stone, 2002).

Proximate and nutrient analyses of edible plant and vegetables play a crucial role in assessing their nutritional significance (Pandey et al., 2006). Compared proximate analysis carried out on the leaves of cassava was used to determine the effect of automobiles fumes and associated pollutants on cassava plants on the road side, as these pollutants change the total composition of the plant nutrient. However, determination of the chemical composition of plants is one of the most relevant methods of tracking environmental pollution and bio monitoring.


The aim of this project work is to determine the effect of pollutants from automobiles on the proximate composition of plants grown in close proximity to roads.


  1. To determine the effect of automobiles pollutants on the nutritional composition of plants beside a roadside with heavy vehicular traffic.
  2. To suggest the continuity of the usage and growing of the plants along heavy vehicular traffic.