Conclusion

The percentage difference in the amount of bacterial growth after three hours was between 80-86% for each soap:

·        Soap = 80.58%

·        Anti-bacterial soap (0.3% Triclosan) = 84.19%

·        Soap containing exfoliating granules (Scrub) = 84.34%

·        Water = 85.34%

·        Neem and Turmeric Preparation (10% Neem + 10g Powdered Turmeric) = 86.99%

These results do not support my hypothesis, where based on already conducted research, I estimated the order of the effectiveness of the cleaning agents. However, these results show that the difference in bacterial growth between the different cleaning agents after three hours isn’t as significant as I thought they would be. My conclusion is that, the effect of scrubbing for 10 seconds with the cleaning agent followed by rinsing the hands with water is effective at reducing the amount of bacterial load by at least 80%. This figure could also be explained by the amount of time spent washing which for this experiment was 10 seconds (For practicality purposes as most people do not wash their hands for more than a few seconds) as opposed to the recommended 20 seconds. 

By using fresh yoghurt to ensure that I had a high level of bacteria initially on the hands, this experiment was a simulation of a real-life situation. In certain situations in real life, the initial levels of bacteria on the hands might be much higher than what was tested in the experiment. We may also knowingly come in contact with pathogenic bacteria. In such situations, it may be advisable to use soaps which will kill bacteria, and scrub for at least 20 seconds. By scrubbing our hands for 10 seconds, we eliminate most of the bacteria, however there is the possibility that the remaining bacteria on our hands may be pathogenic and enough to cause infection. 

I tested the Neem and Turmeric preparation, hoping that it would be as effective as soap, therefore making it an accessible alternate to soap for people living in countries like India, where a significant percentage of the population has access to these plants but not to good sanitation and soap. These results rank this preparation as being quite effective, which would mean, that Neem and Turmeric can probably be used as an ordinary soap.

This experiment could be improved by using a more sensitive method of taking samples of bacteria from the palms and fingers. Swabbing the surface of the hands would pick up only the uppermost layer of bacteria; by using a more sensitive method, I could cement the relationship between the type of agent and its effectiveness. A further improvement would be to standardize the amount of bacteria in the 'Pre-wash' samples.  More research and studies would to be conducted with a larger data set to make a conclusive statement about which cleaning agent is the most effective.