Contaminants in kai – Arowhenua rohe
The reports describes:
1. The methods of sampling & analyses used based upon questionnaires completed by iwi members.
2. Results for bioaccumulative contaminants, e.g. DDTs, PCBs, heavy metals, arsenic.
3. A discussion of the significance of these results to respective Iwi.
4. Recommendations for future research.
Questionnaires were used to survey Arowhenua iwi members about their past and present consumption rates of traditional kai species. Fish and/or shellfish (including longfin or shortfin eel, brown trout, koura, pipi, mussel and flounder) and watercress samples were gathered from multiple important harvesting sites in the different regions, and tested to assess their bioaccumulative contaminant levels. Hair samples were also collected from Arowhenua participants to assess possible exposure to mercury, a highly accumulative contaminant. Analytical data for fish, shellfish and sediment samples was collected for a range of organochlorine compounds, including DDT (historically used as a pesticide), chlordane (a pesticide) and dieldrin (an insecticide), arsenic (As),and heavy metals e.g. cadmium (Cd), chromium (Cr), copper (Cu), lead (Pb), mercury (Hg), nickel (Ni) and zinc (Zn). Eel and/or trout fillets were also analysed for selected polychlorinated biphenyls (PCBs). Watercress was analysed for heavy metals and arsenic only.
High total DDT (ΣDDT) concentrations were recorded in eel fillet from Winchester, Ohapi Creek and Doncaster in Arowhenua rohe. The concentrations of ΣDDT in trout and flounder were generally much lower than for eels. Other organochlorine pesticides were either below the limits of detection, or measured in much lower concentrations than any of the DDT congeners. Polychlorinated biphenyls (PCBs) were analysed in eels from Arowhenua rohe. The most elevated levels of PCBs were found at Doncaster and Winchester. The concentrations of mercury were generally highest in eel fillet whereas arsenic was only present in flounder and trout. The average concentration of mercury in the Arowhenua hair samples was similar to levels found in the study reference group. The low number of Arowhenua responders in this study meant we couldn’t analyse potential links with consumption of wild kai.
The results show that if kai was gathered randomly across all sites throughout the Arowhenua rohe, then there is no significant risk to members of Arowhenua from eating eels, trout, flounder or watercress. If kai was mostly gathered at the more contaminated sites then a significant risk exists when eating eel.
A number of potential “hotspots” (i.e., area of increased risk) were identified for Arowhenua rohe. From the risk assessment, consumption of eel from Doncaster, Ohapi Creek or Winchester should be less than once per month. Furthermore, consumption should also be limited for eel harvested from Waihi River, Temuka, Opihi River upstream and below Pleasant Point to 1- 4 meals/month. With respect to trout, a degree of caution should be exercised when consuming individuals from Opihi River mouth, Temuka or Orari Ohapi. Flounder from Washdyke Lagoon and Orari Ohapi also represent a risk, with allowable consumption limits of 1-4 meals/month. Watercress consumption risk was highest when harvested from the Opihi River (below Pleasant Point site), with consumption limits of 2.7 meals/month.
|
|
Citation proposal
Chris Hickey (NIWA) - Michael Stewart (Streamline Environmental Ltd) - Ngaire Phillips (Streamline Environmental Ltd). . https://dc.niwa.co.nz:/niwa_dc/srv/api/records/086910ac-25f5-76da-cca6-316fb925ff35 |
Simple
- Date ( Creation )
- 2015-06-15T00:43:00
- Date ( Revision )
- 2015-06-15T00:43:00
- Purpose
- The aim of this study was to quantify the risk to Arowhenua iwi members by consuming wild kai gathered from their respective rohe (or regions), e.g. South Canterbury.
- Credit
- Authors: Ngaire Phillips, Mike Stewart, Greg Olsen, Chris Hickey – NIWA Hamilton, Gail Tipa – Tipa & Associates. The research was funded by the Health Research Council of New Zealand, Contract HRC/207. We want to thank Lindsay Hawke and Julian Sykes (NIWA Christchurch) and Te Runanga o Arowhenua members for their participation in the research and for help with field sampling.
- Status
- Completed
Author
NIWA
Point of contact
Author
Streamline Environmental Ltd
Author
Streamline Environmental Ltd
Point of contact
- Spatial representation type
- Vector
- Topic category
-
- Biota
- Environment
- Health
- Description
- South Canterbury-Arowhenua Rohe
N
S
E
W
- TimePeriod
- 2009-09-01T00:00:002011-08-16T00:00:00
-
- Te Runanga o Arowhenua, South Canterbury, biota, bioaccummulative contaminants, organochlorine pesticides, DDT, arsenic, mercury, heavy metals, risk assessment
- NIWA Project Codes
-
- HRC08201
- Use limitation
- Only a small number of people completed the kai consumption questionnaire and only a low number of larger species (i.e., eel and trout) were collected from some sites, therefore, caution must be taken when applying consumption limits on a site by site basis. It should also be noted that only a small amount of the total arsenic detected in the kai samples is likely to be toxic. While our calculations of risk take this into account, without further study we cannot know this amount exactly. Therefore, the risk calculations where arsenic is the main contaminant of concern should be viewed with caution.
- Other constraints
- Data held and available from Te Runanga o Arowhenua, Temuka.
- Use limitation
- Data may be obtained from Te Runanga o Arowhenua or point of contact.
- Classification
- Restricted
- Language
- English
mdb:MD_Metadata
- Metadata identifier
- 086910ac-25f5-76da-cca6-316fb925ff35
- Language
- English
- Character encoding
- UTF8
Custodian
NIWA National Institute of Water and Atmospheric Research
301 Evans Bay Parade
Hataitai
Wellington
6021
New Zealand
- Resource scope
- Dataset
- Date info ( Creation )
- 2015-06-18T08:27:12
- Title
- ISO 19115-3
Overviews
Provided by
Views
086910ac-25f5-76da-cca6-316fb925ff35
Access to the portal
Read here the full details and access to the data.
Associated resources
Not available
NIWA - Metadata Catalogue