INTRODUCTION
Lagos, being the centre of excellence, as other major state capitals in Nigeria, and some developing countries, has the highest concentration of vehicles, and generators in the country(Nigeria).
Being a centre of excellence, also comes with a price. A high one in my view. Increased crime rates, increased health risks as a result of exhaust emissions, etc. But, in my view, it appears states, or countries with issues of environmental degradation from exhaust emissions, place more emphasis on the economic gains from these dangerous sources of "diseases", than on the wellbeing of their population and even the environment.
The trends seems to be changing, with some states, in Nigeria, especially Ogun state, conducting emissions testing scheme in the state. Other states are looking to follow suit. Nigeria, through the ministry of environment, designed and developed a standard for curbing emissions (NESREA Vehicular Emissions Standard 2011).

In 1996, California took the lead in introducing legislation, to force car manufacturers both at home, and abroad, to confirm to a single emissions testing program. In that vein, OBDI and OBDII Protocols were introduced to monitor emissions levels on board vehicles, and other applications. These protocols allows a car's data, such as RPMs, engine temperature, to be recorded on the car's computer system(ECU-engine control unit), and to allow easy access with it using a diagnostic tool.

WHAT EMISSION IS
Emissions are a by-product of the combustion, or the burning of fossil(petrol, or diesel)fuels from internal combustion engine applications, such as mobile (vehicles, ships, and even aircrafts), and stationary (generators, etc).
They contain dangerous greenhouse gases such as carbon dioxide(CO2), carbon monoxide (CO), Sulphur dioxide (SO2), etc, that are know to cause health and environmental problems.
Carbon dioxide, which is the most and common polluting agent would be considered in this article.

MUST THERE BE EMISSION OUTPUT FOR YOUR APPLICATION
No internal combustion engine application, whether its a generator, or a vehicle, can efficiently operate, without the exit of emissions from its tail pipe. If there isn't any emission (smoke) from the tailpipe, it suggests the application in question may already be a "failsafe mode".
I'm not suggesting the emission level in your car/generator, must be a distortion from the set standard in your state, or country.
Different applications emit different levels of smoke(emissions). Diesel applications, for instance, puff out a tremendous mixture of smoke, and particulate matter, some even smaller than the human hair (in microns), on START-UP, and when there's being a deviation from any of it's engine management systems. As those applications age with time, they emit terrible smoke levels. Petrol applications on the other hand, on start up only emit whitish smoke, and within a short while, disappears. A vehicle with lits of smoke levels, whether it's black, blue, or even white in colour, suggests high-level of pollution.
(See Fig1: Diesel truck along Lagos-Abeokuta Expressway)
EMISSIONS COLOUR TYPES
*Black. Suggests the application consumes excess fuel, and needs urgent attention.
*Blue. Suggests excessive engine wear; oil leaks into the intake manifold through the PCV(positive crank case ventilation); oil spills finding it's way
in to the exhaust system.
*White. Suggests coolants leaking into the cooling system; cylinder head problems, etc.

NB: Diesel engines are not supposed to emit visible smoke, when new.
Any diesel applications emitting black smoke, should tell you the engine management systems of the application gas being compromised.

DO EMISSIONS HAVE NEGATIVE IMPACTS
Emissions, though visible and non visible have innumerable negative impacts, on both man, and the environment.
1. HEALTH WISE. The WHO, in 2011, classified diesel exhaust, as a CARCINOGEN This means it's being found to be amongst some of the causes of CANCER worldwide.
Mind how you expose yourselves to diesel exhaust applications.
*Increased risk of respiratory tract infections. People who are asthmatic, are at a greater risks of exacerbating the condition. Continues coughing can be acquired from exposure to emissions.
*low sperm count for men, and frequent miscarriages by women. So, the next time your partner isn't PERFORMING to your expectations vis-à-vis copulation, don't just blame HIM or HER. Inhaled emissions may have being the cause.
*Children exposed to emissions have low assimilation rate. It also causes dizziness.

2. ENVIRONMENT.
The global economy, over the centuries, has being fuelled by fossil fuel applications such as tractors, cars, generators, etc. This has made other countries to be classified as advanced/industrialized, while others, are still reeling in poverty.
The environmental impacts if these advancements, has had innumerable toll in the environment.
For instance, it has led to increased greenhouse gases, which has further increased climate change. It gas caused flooding, food shortages, poverty, and even death in some continents.
Nigeria also, has not being an exception.
3. Others. The more a diesel or petrol application burns fuel, the more it tells on THE POCKET. OK. Why do you think car owners with higher capacity engines(V6- sale such cars. Asides other reasons, fuel economy us the MAJOR reason.
High levels of emissions can cause an accident. For instance, if we were following closely the truck above(Fig 1), we would have had an accident. But thank God, we gave a clear distance, to improve VISIBILITY.

HOW TO CURB YOUR "CIGAR"(EMISSIONS)
*Emissions tests. Some states carry out emissions testing on internal combustion engine applications in Nigeria now.
To get maximal result and cooperation, thus scheme is first made INVOLUNTARY, and later on VOLUNTARY.
You could sign up for a monthly emissions testing scheme, where your car/generators are tested for emission levels. You're issued a certificate if you pass the test, and given a notice of repair and fine, if the application concerned did not pass the test.
Emission rest equipment such as fas analyzers are used in this case.
*Maintenance is the key. If you could put an eye on the type of emissions you could visibly see, that would help a great deal in nipping in the bud, emissions related problems for your car/generators.
If you own a diesel truck/generator, replace the diesel filters as at when due.
Any distortions noticed in the engine management systems should be rectified immediately.
*This would be the big one. Don't board a smoking public transport system. For example, a " danfo" bus visibly smoking. Boarding buses like that, shows you're part of the problem. You're paying those buses to keep polluting the environment, and KILLING PEOPLE. I know a lots if people would disagree with me on this.

CONCLUSION
Owning a car/generator, etc, isn't for fun. Those stuff you've got, without proper maintenance and checks from you, means you're responsible for environmental air degradation, and the deaths of millions of people from emissions related illnesses.
Our priorities should be more of a sustainable future, vis-à-vis health and environment wise, than the present quest for economic gains.

Well, guys, I just hope you learnt something today.
PLS, drop your comments in the comment bar.
Criticisms, and maybe....... Would learn from that!

Regards,
TRYGO