Scientists at the Industrial Technology Institute (ITI) have tested 31 samples of pesticides sent by Registrar of Pesticides (ROP) and found that nine contained arsenic in trace quantities.
Dr Azeez M Mubarak, Director/CEO, ITI told the Business Times that after these test reports were sent to the Registrar of Pesticides (ROP) of the Department of Agriculture, the latter has stopped the sale of these pesticides as an interim measure. According to the ROP, a final decision on the issue has to be taken by the Pesticides Advisory Committee. Analysis of Hg in pesticide samples will commence no sooner the arsenic analyses are completed.
ITI has also tested several samples of rice sent by Rice Research Institute and all of them had arsenic below the detection limit (50 ppb) of the HG-AAS method employed for the analysis.
Dr Mubarak was responding to recent reports where the Customs have sealed some containers of imported pesticides based on the test reports issued by the University of Kelaniya which claimed that these pesticides contained As and Hg at ppb levels.
Dr Mubarak said that many have questioned why ROP uses ITI for testing and not other laboratories. According to the Pesticides Control Act the ROP is empowered to test pesticides only from authorised laboratories listed in the Act and ITI is one of them. According to him, ITI did not achieve this recognition overnight. ITI has been implementing a Laboratory Quality Management System based on ISO Standards since 1996. ITI was the first laboratory in the country to obtain ASTEL accreditation ‘Accreditation Scheme for Testing Laboratories’ a scheme operated by the SLSI. Subsequently with the formation of the Sri Lanka Accreditation Board, the national accreditation body, ITI successfully obtained accreditation as per ISO 17025 standard for several chemical and microbiological parameters.
ITI also been accredited by SWEDAC –the Swedish Accreditation Board for several tests since 2002. Thus ITI test reports are recognised both locally and internationally.
He said that ITI has further expanded its scope of accreditation to include such areas as food analysis, materials analysis and also calibration and noise measurements to meet demand.
According to Dr Mubarak when a laboratory is accredited, it assures its client that the results generated are scientifically valid, legally defensible and that it will be able to provide historical documentary evidence to support the quality of such data. Every year ITI issues more than 12,000 test reports to a client base of 2000 in such areas as exports, for tenders, for regulatory purposes and in the issue of EPLs.
He said that almost all of the test methods used at ITI for the accredited parameters are based on internationally accepted methods such as APHA, AOAC etc. In the event a method has to be modified, the modified methods have to be validated following ISO standards before being accepted for routine testing.
Dr. Mubarak said that after the Bangladesh arsenic problem there was an increasing trend in the world to assess human exposure to arsenic and set safe limits and guidelines to minimise health impacts from arsenic exposure. According to the US Department of Health- ToxGuide for arsenic ‘the general population may be exposed to arsenic in air, drinking water and food. Of these food is usually the largest source of arsenic’. The problem is that arsenic can occur in several different forms in the food, some highly toxic and some with almost no toxicity. WHO has set limits for arsenic in drinking water at 10 parts per billion (ppb) but most Asian countries maintain limits of 50 ppb as their levels routinely exceed 10 ppb. No limits have been specified yet for rice except at 150 ppb in China although CODEX is now in the process of setting standards for arsenic in rice.
Dr. Mubarak said that at present FAO has not set any limits for arsenic impurities in pesticides, except for a few pesticide formulations like copper compounds. He said that setting limits for arsenic impurities in pesticides is not as straightforward as for water or food. It involves a detailed Risk Assessment to find out how much of the arsenic impurities in pesticides will enter the food chain and what impact it would have on the health of the people. |
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