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The Effect of Pesticides on the Blood and Lymphatic System

What is this study all about?

In New Zealand, certain farming occupations have been associated with an increased risk of non-Hodgkin lymphoma (NHL), a common type of blood cancer. Pesticide exposure is likely to play a role, but it is not known which specific pesticides are involved. Studies from overseas have shown that pesticide exposure can result in subtle changes in certain biological markers that can be measured in the blood. This study investigates whether pesticides currently used in New Zealand are associated with biological markers that may play a role in the development of NHL. For this reason we are inviting 100 users of pesticides and 50 non-users to participate in the study. We will measure the levels of selected biological markers in their blood, and investigate whether these markers are more common in users of specific pesticides compared to non-users. We hope that with your help we will be able to identify harmful pesticides and provide opportunities for the development of strategies to reduce the risk of NHL where possible.

Who is invited to participate in the study?

We are inviting 100 healthy individuals who regularly apply pesticides from a range of farming sectors, including horticulture, sheep farming, and plant nurseries. We are also inviting 50 healthy individuals who never applied pesticides as the comparison group.

What does participation involve?

Participation in the study involves:

(1) completing a confidential questionnaire that asks about your health and work history;

(2) donating two blood samples (one before and one during the spray season);

(3) the self-collection of a urine sample.

If you are interested in taking part, we will contact you to arrange a visit by a research nurse at a place and time convenient to you. During the first visit, the questionnaire will be completed and a blood sample taken, which will take up to one hour. A second 30 minute visit will be planned for later in the year, when another blood sample will be taken and your recent pesticide use will be recorded.

What will happen to my information?

All blood samples will be analysed for a range of genotoxic and immunotoxic markers (indicators of genetic damage and immune function). Selected urine samples will be analysed for pesticides and their break-down products. All biological samples will be processed and analysed anonymysed using ID numbers by specialized research laboratories in New Zealand and overseas. The blood tests are for research purposes only and therefore further investigation is necessary by a GP in the case of abnormal findings. In the rare event of findings requiring follow-up by a medical professional, your GP will be informed if you wish us to do so. All information you give us is confidential. Each questionnaire and blood test result will be entered into a database using ID numbers. No individual information or names will be published.

When the study is completed all information will be locked away in filing cabinets, which will be the responsibility of the Director of the Centre for Public Health Research. We will store any remaining biological samples in a confidential manner so that any questions related to this research that arise after the publication of our study can be answered without having to collect new samples. Information and samples provided will only be used for this research and publications arising from this research project. If you want any unused sample returned to you, you can indicate this on the consent form.

You are under no obligation to accept this invitation.

If you decide to participate you have the right to:

  • decline to answer any particular questions;
  • withdraw from the study at any time;
  • ask any questions about the study at any time during participation;
  • provide information on the understanding that your name will not be used;
  • be given access to a summary of the project findings when it is concluded.

If you have any questions about this study, please contact:

the study research nurse: Heather Duckett, Free phone 0800 000544, E-mail,

or the study principal investigator: Andrea ’t Mannetje, Ph: 04-801-5799 Ext 63373, E-mail

Thank you very much for your time in considering this study. We hope that with your help we can improve the safety of pesticides used in New Zealand.