People, places, and things attract and collect both positive and negative energy.  Some people are especially prone to absorbing the energy around them.  It is always a good idea to surround yourself by positive people and avoid places that collect negative energy, like hospitals and cemeteries. 
In the event that you have found yourself spiritually contaminated, a good Santero/Palero/Spiritist should be able to do a consultation with you a prescribe a remedy in the form or a spiritual cleansing.  There are many different types of spiritual cleansings that can be performed for a variety of reasons.  Here are some common examples:
1.)  Personal cleansing - People can attract bad energy to themselves and may need to be cleaned from time to time.  This would typically be prescribed to you during a consultation.  It may be as simple as rubbing fruits across your body and offering them to one of the Orishas or could be more complex and require plants, animals, or a combination of all of the above.
2.)  House cleansing - It is a good idea to use incense to clean your house weekly.  In the event that something tragic has happened at your house you may need a more thorough cleansing to be performed by someone. 
3.)  Business blessing - If you own your own business, there is a simple yet powerful ceremony that you should have a Santero perform for you at the beginning of the year.
Please contact me at 720.257.8539 if you would like to learn more about one of the above cleansings.