The Zika virus is the most recent international health emergency, and has been the centerpiece of debate over the growing threat of epidemics. This is due to the fact that over 33 countries in the Americas have reported cases of Zika, and because an increase of microcephaly cases in Brazil seems to be linked to the virus. Brazil has deployed over 220,000 troops to combat the mosquitoes that transmit Zika with numerous pesticides, which makes us question the effects those pesticides may have on the environment and the population.
Last week, social media was taken by storm with allegations that a larvicide that was introduced to Brazil’s drinking water supply to stop the growth of mosquito larvae is responsible for their increase of reported microcephaly cases.
The Brazilian Health Ministry and independent scientists quickly stepped in to debunk claims of the link between the larvicide pyriproxyfen and microcephaly, stating that such a link “has no scientific basis.” Nonetheless, the report by an Argentine group of doctors, and the University Network of the Environment and Health (UNEH) is reminiscent of books like “Silent Spring,” which despite its scientific discrepancies, captured humanity’s attention of the damaging effects that the pesticide DDT had on the environment, leading to its ban in the U.S. and other countries. Both cases lead us to wonder how we should approach the usage of chemical products. Should chemicals without proven harmful effects be used to combat diseases and pests, or do we owe to humanity to research all their possible effects before using them?
One of the major critics of the report was Dr. Francis Collins, the director of the U.S. National Institutes of Health, who called it a “sketchy” and an “interesting but speculative report.” He may have referred to it as an interesting report for a variety of reasons. The most interesting part about such a report is that if its conclusions were to be true, we would have been guilty of creating a bigger problem trying to combat a virus that until now has simply caused mild effects on humans. Just like DDT, the cure would have proven worse than the disease, and would add to humanity’s recurring problem of implementing defective and harmful solutions that turn out to be worse than the problem they are trying to address.
Which raises the question: Should chemical products be considered innocent until proven guilty? I argue that we shouldn’t make use of chemical products just because there’s no proof of any harmful effects, but rather only make use of such products if exhaustive research fails to point them out.
As more evidence is gathered pointing to the Zika virus as the culprit, most scientists are leaning toward rejecting the conclusions made by the report. The World Health
Organization announced that the causal link could be confirmed within weeks. But, without proof at hand at this point, even the scientists rejecting the claims by the report agree that no theory should be dismissed. In fact, after the release of this report, the state of Rio Grande do Sul decided to suspend its usage of the larvicide, claiming that the “suspicion” was enough for suspension, and that they “cannot take that risk.” Rio Grande do Sul fails to recognize, however, that it already took the risk when they introduced pyriproxyfen to their drinking water supply without exhaustive research of its effects. Chemicals are not innocent until proven guilty, and we should research all the possible effects of chemicals that we make use of before trying to combat diseases or pests with them.