We talk about people being “colour-blind” but very few of us are. Even those who describe themselves as colour-blind are normally just colour lack. A strongly, colour-blind person will still be able to tell 20 different colours, compared to the 100 or so that normal-sighted people see.

Pingelap, a tiny island in the Pacific, is a beautiful spot but one that has a’ genetic trouble. It is known as Colour-blind Island because so many people who live on this remote island can only sec in black and white.

Not being able to see in colour is bad enough. But one is lander, Herrol, who’s a fisherman, also struggles in full sunlight because all he sees is a painful burnt-out image. “I find it difficult to go outside in the sun,” he says, “because when it’s sunny I cannot see to do my work.”

But if being truly colour-blind is rare, why is it that around 10% of the population of Pingelap live in a totally black and white world?

Well, we know that in 1780 the population of Pingelap was all but wiped out by a tsunami (海啸). As few as 20 people survived, one of whom was the king. It’s believed he had a genetic fault that causes colour-blindness and he passed this fault on to his many generations.

There is one advantage. Herrol can see well, really well, in the dark. So when it gets dark, Herrol and his friends get in their boats and hunt flying fish. They hang up flaming torches and the fish are attracted to the flames. “This type of fishing is fun,” Herrol says, “especially if we catch plenty. So even though it’s hard work we enjoy it.”

Even if vaccination (接种疫苗) is a powerful defense against disease, some voices are against it. In a recent letter, the American Medical Association (AMA) urged big social media including Amazon, Facebook and Google to take action to defend medical science on their platforms.

It said that vaccine -preventable diseases that do harm to the public health like measles (麻疹) are on the rise. Measles cases worldwide jumped more than 30% in 2017 compared to 2016, with the largest increases seen among nations in the Americas, Europe and the Eastern Mediterranean. Vaccine-preventable diseases are increasing largely because many people are unwilling to get vaccinated. And some of these people even encourage others to refuse vaccination. So this year, the World Health Organization (WHO) declared the anti-vaccination movement a top 10-health threat.

“Vaccination is one of the most cost-effective ways of avoiding disease—it currently prevents 2-3 million deaths a year, and a further 1.5 million could be avoided if global coverage of vaccinations improved,” WHO said.

A research article published in 1998 in a medical journal suggested a link between a vaccine and the development of autism (孤独症) in young children. Although the research has been suspected and many other studies have proved that vaccinations do not cause autism, the article is still impressing people strongly today. Another reason for the growth in the anti-vaccination movement is widespread misinformation on social media, which can turn people against vaccination.” If a concerned parent consistently sees information in their Newsfeed that casts doubt on the safety of vaccines, it could cause them to disregard the advice of their children’s physicians and public health experts and refuse to follow the recommended vaccination schedule. So access to true information about vaccine safety is badly needed.

A large-scale study has found a link between eating a diet based on organic food and having a reduced risk of cancer. If the new results are confirmed, promoting organic food consumption could be a promising preventative strategy against the disease, a team of researchers from several French institutions said.

Among the environmental risks for cancer, there are growing concerns about exposure to different types of pesticides(杀虫剂) from farming. The impact of such chemicals on the human body is still not well understood but there are some indications that harmful effects can occur even at low concentrations.

Meanwhile, pushed by environmental and health concerns, the organic food market continues to grow rapidly. Organic food is produced without the use of synthetic(合成的) fertilizers, pesticides, genetically modified organisms, and the use of veterinary(兽医的) medications.

"Organic foods are less likely to contain pesticide remains than conventional foods, and studies have shown that an organic diet reduces exposure to certain pesticide," Julia Baudry, lead author of the study from the Centre of Research in Epidemiology and Statistics in France, told Newsweek.

"In the general population, the primary route of exposure is diet, especially intake of conventionally grown fruits and vegetables. However, few studies have examined the association of organic food consumption with cancer risk. "

For the study, published in the journal JAMA Internal Medicine, a team of researchers examined data on the organic food consumption frequency and dietary intake of 68,946 French adults collected by an ongoing survey which began in 2009. They then followed up on these people at various points in the future.

Participants reported how often (never, occasionally or most of the time) they consumed 16 types of organic foods including fruits, vegetables, soy-based products, dairy products, meat and fish, eggs, grains and legumes, bread and cereals, flour, vegetable oils and condiments, ready-to-eat meals, coffee, tea, and herbal tea, wine, biscuits, chocolate, sugar and so on.