In 2002, National Institute of Occupational Health (NIOH), Ahmedabad published a study titled, “Report of the investigations of unusual illnesses allegedly produced by Endosulfan exposure in Padre Village of Kasargode district (N. Kerala)”. It was followed by another study made by the NIOH titled, “Effect of Endosulfan on Male Reproductive Development.” Both of these studies have become available on internet for public access. During thorough readings of these reports, scientists and experts have noted that the studies have several serious scientific errors relating to the residue analysis of Endosulfan.
Analytical Errors in the NIOH report
The NIOH report named ‘Report of the investigations of unusual illnesses allegedly produced by Endosulfan exposure in Padre village, of Kasargode district (N. Kerala),’ had fundamental inconsistencies as was observed by scientists and experts.
Chemical residue analyses are performed on a sophisticated analytical instrument known as Gas Chromatography (GC) fitted with an Electron Capture Detector (ECD). Each GC-ECD has a lower limit for the minimum amount of a chemical that it can detect. This is expressed as Instrument Detection Limit (IDL). For the study under question, the NIOH had used GC-ECD (HP Model 6890) with the minimum IDL of 1 part per billion (1 ppb) for Endosulfan. In other words, the instrument used by the NIOH could not detect Endosulfan residues lower than 1 ppb. Yet, the NIOH report carries residue findings as low as 0.4 ppb and 0.5 ppb. Simply put, the residue levels reported by the NIOH fall below the minimum detection limit of the instrument used. These findings are scientifically indemonstrable, and are false and incorrect claims.
Since, the raw data recorded by the NIOH for generating Endosulfan residue data in water, soil and blood samples were fundamentally flawed, its subsequent analysis is even more peculiar. For instance, the table no. 4 in the report shows the total Endosulfan (ppb) in six samples as 0.030 ± 0.18. Annexure -8 shows ß Endosulfan residues as 0.0005± 0.001. It may be observed here is that the standard deviation goes beyond the mean (average) by up to 500 per cent.
The Most Clinching Evidence: Modern GC-ECDs are fitted with computers that process the data gathered from the detectors into chromatograms and finally produce an easy-to-view report. Normal practices of a residue-testing laboratory require that copies of chromatograms of analysed samples are retained and stored in the laboratory/computer for future reference in case of any dispute. Therefore, letters were sent to NIOH under Right to Information Act (RTI Act) seeking copies of chromatograms relevant to this study. NIOH did not respond to requests for parting with raw data until the intervention of the Chief Information Commissioner. The case was heard at the Information Commission and it took three hearings and two orders by the Chief Information Commissioner for NIOH’s appellate authority to finally handover the 1,700 pages of raw data. The varying and inconsistent excuses given by the NIOH while refusing required information under the RTI Act were revealing signs of a cover-up. On examining the data, experts learned that the analysis conducted by NIOH had sure laboratory failings. The conclusions drawn did not corroborate with the raw data and the complete analysis is now being believed to be forged.
Many erroneous reports emerged after the NIOH study that was proved to be fundamentally flawed. Among these was another noted NIOH report, ‘Effect of Endosulfan on Male Reproductive Development.’ Kasargod-based NGO Thanal, Centre for Science and Environment (CSE) and National Institute of Occupational Health, Ahmadabad (NIOH) have all produced reports linking Endosulfan to adverse health problems including cancer, infertility, birth defects and neurotic disorder. There were numerous scientific flaws in these reports too. For instance, CSE found Endosulfan residues of 9.91 ppm (parts per million) in filtered water samples taken from Padre village. The dissolved chemical concentration in water cannot exceed the solubility of the chemical. Endosulfan’s water solubility is 0.32 ppm. The analytical methodology used by CSE for estimation of Endosulfan residue was scientifically incorrect and inconsistent. CSE’s claim of 9.19 ppm is scientifically implausible. It violates the basic laws of chemistry.
Supported internationally by PAN, EJF (Environment Justice Foundation) and I-PEN (International POP’s Elimination Network) NGOs with vested interests have effectively used media to generate a negative public perception of Endosulfan. Despite the inconsistencies, international conventions and regulatory authorities worldwide have referenced the NIOH report while reviewing Endosulfan, including the Rotterdam and Stockholm Conventions. Recently, the National Human Rights Commission has pressed the Central Government for a nation-wide ban on Endosulfan based on the same report.
