1985 / 86, 1998, 2002 soil & 2004 blood serum 2,3,7,8-TCDD testing confirmed significant historic TCDD exposure to a 'Paritutu' population ESR 2004 / 2005 estimated at approximately 1700 living near the plant. It is likely the principal TCDD releases were from 2,4,5-T manufacture 1964-69 inclusive [Pilgrim R., 1986]. An update of the NZ Paritutu blood serum TCDD exposure data was published in Chemosphere May 2009:

Community research based on corrected blood serum data has confirmed highly significant 2004 above background blood serum 2,3,7,8-TCDD increases were exclusive to 1960 to 1972 Paritutu residents.

A 2010 CPHR report on 1965-70 birth defects at Maternity Hospital found significant increases for All Defects, Congenitally Displaced Hips, Hypospadias, Talipes, Spina Bifida and Neural Tube Defects.

The 1966 census population was 31,843 and 34,165 in 1971. It is likely that around 10 % to 20 % of all WMH 1965 to 1970 births were referral births from other outlying regional Maternity Annexes.

WMH 1965-1970 rates of Hypospadias and Spina Bifida appear to be higher than rates at NWH 1964-67, Dunedin 1967-73 and Northland 1966-77 and 1961-64 rates of 24 cities reported in the 1966 W.H.O study.

WMH 1965-1970 rate of Hydrocephaly that is not reported in CPHR 2010 appears to be three times the rate of Northland 1966-77 & 2nd highest as compared to 1961-64 rates of the 24 cities in the 1966 W.H.O study.

WMH 1965-1970 rate of Talipes appears to be higher than rates at NWH 1964-67 and Northland 1966-77 and second highest as compared to the 1961-1964 rates of 24 cities reported in the 1966 W.H.O study.

The only official health report targeting significantly exposed residents is TDHB Aug. 2002. TDHB August 2002 reviewed the urban New Plymouth addresses, for 13 Anencephaly and Spina Bifida cases among 167 overall defect cases from 5392 live and stillbirths 1965 to 1970; plus 4 Anencephaly & Spina Bifida cases [NTDs] found in WMH ward records from a total 7183 live and stillbirths 1965 to 1972.

TDHB August 2002 reported that three 'Paritutu' NTD cases were found around the ex IWD 2,4,5-T plant when 1 was expected. Addresses for 8, of 28 NTD defects 1965-70 were lost to follow up in TDHB 2002.

Based on address located NTD cases in TDHB August 2002 [with 8 defects lost to follow up] using 1966 and 1971 census populations of New Plymouth and Moturoa suburb around the ex I.W.D plant with crude birth rates the 1965-70 Moturoa rate of US I.O.M herbicide associated NTD defects was 4.4 times the reported N.P rate and the 1965-1972 Moturoa rate of NTD defects was 4 times the reported N.P rate. The Moturoa 1965-70 NTD rate was 2.2 times the 1969-80 NTD rate of N.Z 2,4,5-T sprayers and the Moturoa 1965-72 rate was 2 times the 1969-80 NTD rate of N.Z 2,4,5-T sprayers, from Smith et al., 1982.