Nanofertilizer may create new potential risks since they are more reactive, greater access than larger particles to humans and may affect human immune system and longer time. Human may have nanomaterial and get sick because the defensive system is not good at removing nanomaterial which is more adhesive and easy to infiltrate into human tissues and cells.

In addition. the workers in nanofertilizer fabrication may have higher levels of nanomaterial exposure than the public. furthermore, the farmer and the workers who applied nanofertilizer are also more vulnerable to nanomaterial exposures. Therefore, a durability and good protector such as a new masker and glove must be worn all the times when applying nanofertilizer. The standard procedure operation (SOP) when applying nanofertilizer should be more detail and accurate than SOP in ordinary chemical fertilizer.

Reference 

Societal Implications Of Nanotechnology In Soil Improvement Environmental Sciences Essay. http://www.ukessays.com/essays/environmental-sciences/societal-implications-of-nanotechnology-in-soil-improvement-environmental-sciences-essay.php

I will go  a step further  over what Golam  rightly expressed. These nanofertilizers especially Zn is used in fruit juice packaging as antibacteria/fugicide , and there is very little knowledge on the shelf life of juices packed under the use of nanoparticles.

Dear Saelh,

While synthesizing of nano materials under laboratory , it is necessary working environment with safety measures. I had personal experience on dry cough and fever. In order to overcome protected atmosphere required. I had impregnated  amine nitrogenous fertilizer to nanoporous materials and biosafety were studied with seed invigoration test,  microbial toxicity ,  earthworms system.

Thanks for all answers.