There is no reliable method to predict the depth at which narcosis becomes noticeable, or the severity of the effect on an individual diver, as it may vary from dive to dive even on the same day.Significant impairment due to narcosis is an increasing risk below depths of about 30 m (100 ft), corresponding to an ambient pressure of about 4 bar (400 kPa). Most sport scuba training organizations recommend depths of no more than 40 m (130 ft) because of the risk of narcosis. When breathing air at depths of 90 m (300 ft) – an ambient pressure of about 10 bar (1,000 kPa) – narcosis in most divers leads to hallucinations, loss of memory, and unconsciousness. A number of divers have died in attempts to set air depth records below 120 m (400 ft). Because of these incidents, Guinness World Records no longer reports on this figure.Narcosis has been compared with altitude sickness regarding its variability of onset (though not its symptoms); its effects depend on many factors, with variations between individuals. Thermal cold, stress, heavy work, fatigue, and carbon dioxide retention all increase the risk and severity of narcosis. Carbon dioxide has a high narcotic potential and also causes increased blood flow to the brain, increasing the effects of other gases. Increased risk of narcosis results from increasing the amount of carbon dioxide retained through heavy exercise, shallow or skip breathing, or because of poor gas exchange in the lungs.Narcosis is known to be additive to even minimal alcohol intoxication.
Zygmunt Gloger in his Encyklopedia staropolska mentions that the Polish plait (plica polonica) hairstyle was worn by some people in the Pinsk region and the Masovia region at the beginning of the 19th century. The Polish plait can vary between one large plait and multiple plaits that resemble dreadlocks. Dreadlocks are also worn by some Rastafarians, who believe they represent a biblical hair style worn as a symbol of devotion by the Nazirites, as described in Numbers 6:1–21. By culture
Locks have been worn for various reasons in each culture. Their use has also been raised in debates about cultural appropriation. Africa
Maasai warriors are known for their long, thin, red dreadlocks, dyed with red root extracts or red ochre.In Nigeria, dreadlocks are viewed in a negative light due to their stereotypical association with gangs and criminal activity; men with dreadlocks face profiling from Nigerian police. Australia
Some Indigenous Australians of North West and North Central Australia, as well as the Gold Coast region of North East Australia, have historically worn their hair in a locked style, sometimes also having long beards that are fully or partially locked. Traditionally, some wear the dreadlocks loose, while others wrap the dreadlocks around their heads, or bind them at the back of the head. In North Central Australia, the tradition is for the dreadlocks to be greased with fat and coated with red ochre, which assists in their formation. Buddhism
Within Tibetan Buddhism and other more esoteric forms of Buddhism, locks have occasionally been substituted for the more traditional shaved head.