The agency said that soil quality in the conflict area of southern Lebanon had been affected by the spread of heavy metals and toxic compounds, with "white phosphorus usage further reducing fertility and increasing soil acidity."

SOIL SCIENCE

Farah and other farmers estimate they have already lost up to $7,000 each in potential income, as continuing bombardment has made it too risky for them to plant or harvest the usual seasons of wheat, tobacco, lentils and other greens. 

Oday Abou Sari, a farmer from the southern town of Dhayra, said white phosphorus had also burned hay he had gathered for livestock and even plastic irrigation pipes across his fields. 

"I have to start all over - but first, I need to know if it's safe for planting," said Abou Sari. 

To find out if the white phosphorus has left a lasting impact on their soil, farmers are digging in - literally - and sending samples to Dr. Rami Zurayk, a soil chemist at AUB.

Zurayk developed a research protocol to collect and examine the samples. First, soil is gathered at various distances from the impact site, including a control sample from 500 meters away - which would not have been directly affected by the strike. 

Once in his lab, the soil is sifted, mixed with acid and exposed to high heat and pressure. A solution is added to show the concentration of phosphorus, with the intensity of colour in the result matching the concentration of the phosphorus. The sample is then compared to the control, which sets the benchmark of naturally-occurring phosphorus in the soil. 

"What we're looking for is what happens to the soils and to the plants in locations that have received white phosphorus bombing. Does the phosphorus remain? In what concentrations? Does it disappear?" Zurayk told Reuters. 

His assistant, doctoral student Leen Dirani, told Reuters she had thus far tested samples from four towns this way - but they need more samples to "obtain a conclusive outcome."  

But the steady pace of Israeli shelling on southern Lebanon - particularly agricultural fields that Hezbollah fighters are accused of using as cover - has made farmers unwilling to venture out to gather more samples. Some, like Abou Sari, have left Lebanon altogether. He is waiting out the war abroad and so for now is unable to obtain soil samples.