Science journalists must help to root out misleading scientific claims, but not without sensitivity to culture and the limitations of science.
Over the past few years, Western journalists and commentators have increasingly attacked spurious scientific claims, exposing them as "bad science". 
The targets of their attacks range from claims that the MMR vaccine against three childhood diseases (measles, mumps and rubella) raises the risk of autism, to denials of the scientific consensus that global warming is primarily the result of human activities.
Several practices that have come under fire take place in the developing world. Some are relatively low-risk, such as homeopathic medicine. Others may have more harmful consequences.
The belief of former South African president Thabo Mbeke, for example, that there is no causal link between HIV infection and AIDS, led to the government's reluctance to pay for antiretroviral treatment, resulting in an estimated 300,000 deaths. Criticism of Mbeke's stance only seemed to harden his position.
All such claims need to be contested. Science journalists, and bloggers, have an important role in this process. But the criticisms need a dose of cultural sensitivity if they are to be effective — and to avoid a potentially counter-productive backlash.
This is not to say that culture alone should determine how science is interpreted. But science journalists and commentators should not overlook the limitations of Western science as a way of understanding all aspects of the world, and thus of improving the quality of life.
Where 'bad science' is exposed, the warning is clear: those who ignore the findings of modern science do so at their peril. At best, the argument goes, using bad science can lead to wasted resources. And at worst, it can delay action — to curtail global warming, for example, or protect people against a fatal disease.
The value of such warnings is obvious. Any society that promotes the idea that decisions should, where possible, be based on the best available scientific evidence must also be able to distinguish between good and bad science in order to judge what evidence counts as the best available.
But making such a distinction can appear to be asserting the superiority of Western science over other forms of knowledge, including traditional knowledge, and the belief systems on which they are based. And it can be perceived as furthering the economic and political goals of Western nations (often former colonial powers) in the developing world.
One such case was the opposition to vaccination campaigns against polio in northern Nigeria at the beginning of the last decade. The argument made by Muslim political leaders was that the vaccines produced by Western pharmaceutical companies were being used as a surreptitious way of reducing male fertility — and thus population growth.
So effective was their message that the vaccination campaign stopped in its tracks. And subsequently, spread of the disease delayed global eradication. The experience is a sobering reminder that, even if the science is right (or 'good'), it may not be enough to ensure that it is used effectively.
Public health professionals need to be sensitive to the cultural and political environment in which they operate, and in particular to factors which may lead to solid scientific evidence being rejected.
For example, researchers only recently found that the tropical disease Buruli ulcer is caused by a bacterium. Lacking a medical explanation, people often believe it represents a curse made by one villager against another — so sufferers have traditionally been kept hidden. Such beliefs will need to be taken on board in planning prevention strategies to counter the disease.
These cases spell out the danger facing sceptics who bemoan the ease with which 'bad science' can be peddled to a credulous population, whether in the developed or the developing world. Accusing someone of being naïve, or worse bigoted, in believing a particular argument is unlikely to change their mind.
Without question, revealing the flaws in such arguments is important. This may include emphasising the lack of reliable evidence of effectiveness that can withstand rigid scientific scrutiny.
Science journalists, and their colleagues in the blogging community, are well placed to help with this task. They have a responsibility to not only explain the significance and potential impact of new scientific discoveries, but also to challenge suspect claims to scientific validity.
Strengths and weaknesses
But like other sceptics, science journalists need to develop a sensitivity to the cultural setting in which they are reporting. This can mean going beyond the headline facts of a story — such as the rejection of polio vaccines in northern Nigeria — to unveil the social and political factors behind them.
It also requires developing an awareness of both the strengths and limitations of the scientific method. The strengths lie in the robustness of experimental techniques that distinguish reliable from unreliable knowledge, the key distinction between 'good' and 'bad' science.
Its weakness, however, lies in encouraging a form of hubris where modern science is seen as the only source of reliable knowledge — and discounting, for example, applications of traditional knowledge that may have served communities well for centuries or offer an alternative where science provides limited insight.
The ability to expose and root out 'bad science' should be an essential part of any science journalist's skills. This requires an understanding of how claims can be tested for their robustness (for example, by controlled trials in the case of new drugs).
But some scepticism towards science itself should also be part of this skills set. This should include a reluctance to accept without scrutiny everything that is said in the name of science, even by eminent scientists.