Professor Ibrahim Baba Yakubu is the immediate past Dean, Faculty of Earth and Environmental Sciences, Bayero University, Kano. In this interview with AgroClimateNews he explains how chemicals affect the environment, agriculture and the danger of removing Geography from the curriculum of secondary schools in some states. Excerpt:
By Gambo S. Nababa
What are those chemicals that are being used at work places and homes that are hazardous to the environment?
The issue of chemicals has a very long history especially if one goes back to the beginning of the industrial revolution, because that was the time when we had massive and phenomenal use of a series of chemicals. When we talk about chemicals, borrowing from Chemistry discipline, they are substances or what the chemists call matter, which have defined composition and characteristically, they have defined structure, that is to say they can be characterized on the basis of this composition and then their structure.
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When it comes to the chemicals being used today, with the advent of industrial revolution, rise in manufacturing, transportation, household use, a series of chemicals are being used, and in the process of the usage by various segments of society, especially transportation and manufacturing sectors, a series of chemicals are required. The most used chemical in the manufacturing sector is sulfuric acid. I know it will frighten us as Nigerians to talk about this. It is one of the most used chemicals especially in the manufacturing sector and there are a series of other such chemicals.
By their nature, chemicals can be categorized broadly into two: organic and inorganic chemicals and they can come in various forms. Some can be solid, some liquid and some can be gaseous.
How do chemical substances affect the environment?
They massively affect the environment, and perhaps, maybe that is why God has chosen to put some of these chemicals, especially the heavy metals, deep down in the rocks where they are hidden. Chromium, zinc, lead, most of these chemicals are buried in the rocks. It is when man decides to go into the rocks to mine gold, copper etc that he fetches some of these substances, predisposing them on the land and then before you know they go into the food system.
Additionally, especially the inorganic chemicals that we use in agriculture, nitrogen, phosphorus, potassium, that are used in the production of fertilizer also, cause a lot of problems.
What are the effects of use of chemical on the environment?
The effects of chemicals are multifarious, because in the first instance it is one of the key reasons why we have climate change that we talk about today. Some of these chemicals are sent into the atmosphere to become greenhouse Gases (GHG), such as carbon dioxide, nitrogen oxide, and sulfur dioxide. All of these are gases and they are also chemicals. They are already causing phenomenal change in the average temperature of the planet Earth.
Before the advent of industrialization and massive use of these chemicals, the temperature of the planet Earth had remained at 15⁰c for 15 thousand years, but immediately after industrial revolution, and then massive use of these chemicals, the temperature of the world has risen by about 0.7⁰c, and even the carbon dioxide level in the atmosphere has also skyrocketed because of the massive usage of chemicals.
The effect of this is phenomenal especially if you want to take all the various segments of the environment: for example if we take the atmosphere, we have climate change; take water, fishes are dying because the quality of the water has changed. If you ask chemists to give you a profile of the water we drink today, even the ground water, you find the presence of some of these chemicals inside.
Specifically, how does the use of chemicals in agriculture affect the environment?
Agriculture has been assumed to be one of the key polluters of our environment because of industrialization of the sector. Industrialization of agriculture presupposes that the sector has welcomed the use of a series of chemicals and machineries. Mechanization, use of pesticides, herbicides, rodenticides, etc, all these have the potential to negatively impact the quality of the environment, and the most disturbing scenario is when they begin to get into the food system. What that means is that if these chemicals get into the food system, people will be predisposed to all manner of diseases, and that is the situation we are in already.

What is the way out between using and not using the chemicals by farmers to increase yield?
Chemical fertilizers have the potential to increase yield, but is it sustainable? It is not sustainable. It increases yield to a particular benchmark or time frame. What the chemicals do, I mean the fertilizers being produced for farming, is that they give farmers massive crop yield in the first one to five years and after that they interfere with the natural set up, by attacking micros in the soil. The micros are living things, and they are the rechargers of the fertility of the soil. Fertilizers are like raw salt and when farmers put them, because the micro organisms in the soil are not wearing cloth, they don’t have umbrellas, they are not protected, so the chemicals will kill them and when it kills them what happens is that they render the soil infertile, such that the more fertilizer farmers add, the less crop they will have, and that is the scenario we already have in the country today.
In the late 60s and early 70s when massive usage of fertilizer started, you talk to a farmer and he told you that in this one hectare plot of land he was getting 30 bags per annum but today if you go back to the same farmer he would tell that hardly he gets three bags, because all the micros have been killed by chemicals.
Most people seem not to be aware about the implications of the use of such chemicals, what is the best way to sensitize them?
The best way to sensitize people is to do exactly what the press men are doing, but it is not just to publish the sensitization in the dailies, there is also need to use other media such as radio and television to reach out to people. The government, through the extension service, should also reach out to communities and get it across to them that these chemicals have the propensity to compromise the quality of not just the environment but their health and well-being. When they get into the food system they cause a lot of problems that is why we have a number of diseases today because most of these chemicals are getting into the water, are getting into the atmosphere and are getting into the food system.

When you go to developed nations what one finds is that people are leaving the conventional foods and are going back to organic foods. Conventional foods are those produced from these chemicals, fertilizers, herbicides and so on. While the organic foods are those that are produced the way our fore fathers were doing with organic manure and they were cultivating healthy foods and doing sustainable agriculture. They were not killing the micros, because when farmers apply manure the micros want that. It creates niches for them to multiply and prosper and then they will increase fertility status of the soil because they are complementary to agriculture. But when farmers begin to use conventional fertilizers in the soil they are telling the micros to go and die, and when that happens the soil also dies with the microbes.
Mercury is said to be one of the common poisonous chemicals to the environment hence its health effects could be permanent. What are the common hazards the chemical (mercury) poses to the environment?
Mercury happens to be one of the groups of chemicals chemists categorize as heavy metals. Heavy metal is any particular chemical that has a mass beyond five grams per cubic centimeter. If it has that, it means it is heavy metal and what that also means is that one part per million of it, if a living organism takes in that, either as food or it gets into somebody’s blood stream, it has the propensity of debilitating that person, and that was partly what happened in Zamfara state when there was lead poisoning. Lead, like mercury, is also a heavy metal, and a small dosage of it, one part per million, in fact in some cases, one part per billion, if ingested either through injection or eating, causes a lot of problems.
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Mercury is semi liquid, and because it is so, it has more likelihood to get into the atmosphere, or into water especially, unlike when it is solid. Depending on the type of the heavy metal, but in the case of mercury it is semi-liquid, and that is why people are always conscious about mercury being more dangerous.
The Federal Government has repeatedly said it would phase out chemicals like mercury but not much has been done, how can this be achieved?
I think we must give a little credit to the Federal Ministry of Environment especially with the inception of the National Environmental Standard and Regulation Enforcement Agency. We are not saying they are there; they are not there yet, but they have been trying because they have been checking most of the activities of industries in major cities. For instance I know in Kano, they came and warned tanneries about using chromium, which is a heavy metal. They said if elsewhere ,people are changing to organic tanning, why must our tanneries continue with inorganic tanning, using chromium. So at least sensitization is being done, they are trying to put things in proper perspective so that later they could do better.
What else do you have to say on the danger of chemicals in our environment?
We must get people educated about the environment. In fact, nothing stops the government from mainstreaming environmental study in the curriculum of primary and secondary schools, and it is at this stage somebody would be worried if one gets to hear that Geography is no longer being taught in secondary schools, especially in northern Nigeria. This therefore means all these issues about environmental quality, about chemicals use, about safety choices, cannot be made available to the general populace.
One of the key things that could be done is to mainstream environmental education. Courses such as Geography, Social Studies, Biology and Chemistry should be taught early enough. Nature study should also be introduced at primary and secondary schools. All the states that have expunged or removed Geography as part of the curriculum of secondary schools should bring back the subject, because we are losing the quality of the environment and the only way we can save it is to get people aware about all of these issues. If people use insecticides in their homes, we must teach them to know that these chemicals are dangerous, you can’t put your baby on the bed and then flit the room because when it gets into him, it causes a lot of damage that may not manifest immediately.
By AgroClimate News