Pesticides are meant to stop pests and diseases invading our crops.

But what happens when they leave an after effect long after use?

What happens when their residues cannot be easily neutralized by the environment?

Such is the fate of a special type of organochlorine pesticides called Persistent Organic Pollutants (POPs).

Though a number of them have been banned, their after effects still linger in our environment long after their use.

But most worrying are those chemicals which not only take long to break down but also promote health complications like cancer.

Though a number of POPs residues are considered toxic, there’s insufficient evidence linking most of them to cancer in humans.

Except one…

LINDANE

Lindane is a banned pesticide adversely categorized by the International Agency for Research on Cancer as a human carcinogen.

Exposure to it over time is associated with instances of Hodgkin lymphomas and possibly liver cancer.

Before it’s ban in Kenya in 2015, lindane had been used as a broad spectrum pesticide targeting a number of pests and diseases.

Though it’s use has generally been suppressed ever since, it’s residues in the soil and vegetation has generally remained unaltered because of it’s poor biodegradability.

The presence of lindane in agricultural soils may lead to uptake of these pollutants by crops thereby introducing them into the food chain.

SOIL REMEDIATION

Several strategies are useful in remediation of pesticide polluted soils.

BIOCHAR

Being a carbon based material produced at high temperature under limited oxygen, biochar possesses a highly charged porous structure capable of trapping unwanted substances in soil.

It has been tried and tested in removal of toxic metal, pesticides and even petrochemical pollutants from soil with great ease.

But biochar also provides pores conducive for microorganisms some of which help in natural degradation of such pesticides.

Biochar could be produced from many forms of agricultural waste such as maize cobs or sugarcane bagasse.

COMPOST

Compost is formed when rotting organic matter such as kitchen waste or manure is aged over a period of at least 6 months in a dry, oxygen-poor chamber.

This volatilizes excessive nitrogen leaving a carbon-rich mass laced with nutrients which are good for farming.

Application of compost to soil impedes the uptake of residual pesticides like lindane.

This makes it a very formidable material for soil decontamination.

IN CONCLUSION

Pollution of agricultural soils by pesticide residues is an issue of concern especially since these soils are used for food crop cultivation.

More strategies of soil decontamination and suppressing excessive pesticide use must be promoted for sustainable food production to be a reality.

#justsayin