DDT,

the world’s first synthetic modern insecticide, rose to prominence in the US during World War 2 for its use against disease vectors and crop pests. It emerged from academia at a time when agricultural productivity was at an all time low and malaria was claiming more lives than the war itself. Facing this bottleneck of existential crises, US leaders turned their attention to DDT. Needless to say, the newfound wonder drug saw a swift and unchallenged rise to the top, where it was bankrolled into mass-scale production before steadfastly becoming the cornerstone of US public policy. Advocacy campaigns and television commercials were implemented with near immediate success, giving rise to an overwhelming consensus of public acceptance. Indiscriminate fogging ensued on the back of this and from beaches to schools, children and families were seen frolicking in the fog trails of the ‘mosquito man’ and his chemically-armed truck. Dystopian as it seems, chasing the mosquito man became an after-school pastime for many wartime children. Even today, boomers hark back to ‘the good old days’, telling their tales with the same glossy-eyed smile as with rotary dial phones and glass-bottled milk.

However, after America was whitewashed of its malaria epidemic and had emerged from the war as victors, the mosquito man was no longer the symbol of hope he once was. Amid the early stages of the environmental movement, small outreach groups, concerned with the unregulated spreading of an unknown and invisible substance, began making noise. Seldom drawing any attention, their concerns largely went unnoticed, until the release of Rachel Carson’s ‘Silent Spring’ in 1962. Shedding light on the potential dangers of indiscriminate chemical usage, Carson not only brought body to the concerns of those before her, but essentially set in motion the phasing out of DDT. Fear propagated fast in western societies and it wasn’t long before the first countries - Sweden, Norway, and Hungary, among others - enacted bans on DDT usage. 

Just as this list grew to include global superpower and leading manufacturer, US, evidence of thinning egg-shells and damaged bird populations were being attributed to DDT. It transpired that the very property which put DDT on the map, its environmental persistence, was also its achilles heel. Whilst there was evidence enough to invoke the prohibition of DDT across all agricultural use, no conclusive proof could yet be found of its risk to human health. In fact, the EPA conducted 7 months of investigative hearings, which determined that ‘DDT is not a safety hazard to man when used as directed’ and ‘is extremely low in acute toxicity’. The EPA authorised the US ban on DDT usage just months later and although it made an exemption for medical emergencies, it was an afterthought that would prove woefully ineffectual in the years to come. 

In keeping with general consensus after the ban, various aid organisations, notably USAID, stopped funding overseas disease control programmes that involved the purchase of DDT. At the same time, a gradual halt in U.S production caused prices to surge. Disease-burdened nations were now hit with a fiscal calamity: not only were they refused financial support from western aid organisations but any purchasing options left were no longer feasible. Even those that wished to continue faced unrelenting peer pressure from both environmental lobbyists and the WHO’s own malaria program, Roll Back Malaria, which actively discouraged the use of DDT. The monopolising effect meant that many of these countries, such as Belize, Madagascar and Bolivia, were coerced into establishing their own DDT bans. Unsurprisingly, subsequent decline of the chemical was met with an equal and opposite surge in malaria cases, allowing a sobering death toll to accrue.  

By the early 2000s, research that had been lacking in the mid 20th century was  finally carried out  by the CDC and WHO, both of whom concluded that DDT was only ‘mildly harmful’ to humans and possessed extreme benefits which outweigh the negatives in many scenarios. This led to the 2001 Stockholm Convention, signed by 152 countries, banning all agricultural use of DDT and permitting only very limited use for malaria prevention. A few years later, in 2006, WHO declared their formal position on DDT, endorsing its use for indoor residual spraying in order to rapidly reduce the number of malarial infections. Perhaps the dramatic impact of DDT is best summed up by India, who’s indoor spraying programmes reduced malaria deaths from nearly 1 million in 1945 to just a few thousand in 1960. The exact opposite was observed in South Africa, a 1000% increase in malaria cases between just 1995 and 2000, the same time period in which DDT was discontinued. 

Years on, investigations into the health effects of DDT have continued, only to return weak or inconclusive results, and although largely unaccountable at this early stage, conclusions around tertiary impacts indicate a similar trend. That being said, some relationships have been earmarked as potentially harmful and it is important that these are not ignored. Any potential residual effects should be afforded careful consideration and so it is absolutely imperative that objective research on the matter continues long into the future. Fortunately, this seems to be taking place; a series of recent laboratory tests rendered DDT a probable carcinogen after the development of liver tumours was discovered in animals. 

Despite such emergence of new evidence and ongoing concerns, the weight of certain statistical distinctions are undeniable in bringing an end to the controversy. For example, DDT’s death toll, to date, stands at 0. In comparison, the average yearly minimum death toll for malaria, accrued over the last 27 years, stands at 619,000. When further considering that DDT remains the most effective and readily available medical solution to malaria, it becomes hard to justify any accusation of its threat to human health. Now, with all the benefits afforded to us by hindsight, we are better able to put this controversy in perspective. Whether you subscribe to utilitarian notions or not, the ‘net good’ of DDT, at this early stage at least, is every bit worth its continued but careful usage.