Four cities study
The Chinese government and the US Environmental Protection Agency (EPA) recently conducted an epidemiologic study of children’s and adults’ respiratory health in relation to their exposure to both ambient as well as indoor air pollution in urban and suburban districts of China.

Called the Four Chinese Cities Study, 7,621 school going children residing in eight districts of Lanzhou, Chongqing, Wuhan and Guangzhou were covered. It measured the ambient particulate matter present in these cities and also took into consideration various risk factors like home environment, parental smoking, history of parental asthma, having been breast-fed and gender.The prevalence rate for wheeze, asthma, bronchitis,hospitalisation due to respiratory diseases, persistent cough, and persistent phlegm was calculated.

Positive associations have been found between morbidity prevalence and ambient levels of coarse particulate matter (PM) which range in the size of PM10-2.5. The evidence of association between levels of nitrogen dioxide and sulphur dioxide and children’s respiratory symptoms though present, is weaker than that of PM.

Immunological exposures
The greatest risk of exposure to various petroleum derivatives is experienced by the petrol filling station workers. Long term exposure to such derivatives is known to bring out immunological changes in the workers. A two year period study was done on 89 male petrol filling workers of Hyderabad and Secunderabad, belonging to the age group of 20-45 years and working for a period of 2-18 years.

The study measured the activity of serum adenosine deaminase (ADA), which is an enzyme important for developing cell immunity. ADA activity increases during the body’s imunnological responses. The research has been inspired by an earlier study on the role of serum ADA activity in tobacco factory workers who were occupationally exposed to tobacco dust and were found to have increased ADA activity as compared to control group. A marginal increase in serum ADA activity of petrol filling stations workers has been reported in this study but the research calls for further insights to substantiate the findings.

Tylenol blues
Tylenol, the most popular non-prescription drug of the US has been found to have an important role to play in causing liver damage. Study conducted over a period of 25 years by the Food and Drug Administration (FDA) advisory panel shows that acetaminophen, the active ingredient in Tylenol causes liver disease. More than 50 million Americans use Tylenol every year. How much of it is safe and can small doses also be toxic is the question now being asked. Says Kate Trunk of the FDA, " You cannot allow more innocent men, women and children to suffer." Her own son died from liver disease after taking acetaminophen drug on injuring his wrist.

The drug manufactured by Johnson & Johnson (J & J) carries no reference about its potential side effects on its packaging. On the contrary, its campaign once boasted of "nothing's safer" but the reality now is something different.

Over dose of acetaminophen in itself is responsible for more than 56,000 emergency room visits every year in the USA, with more than 100 being fatal. According to William Lee of the university of Texas Southwestern Medical Centre, acetaminophen is the leading cause of liver failure. Treatment of tylenol related cases is rarely successful. After a while, J & J included a warning with each adult Tylenol package noting that the liver damage could be due to the mixing of the drug with alcohol and the drug by itself was safe.

For the warning to become mandatory, the FDA has to formally adopt the recommendation.

Poisoned fragrance
Lead is added to candle wicks to stiffen them and to let them burn for longer time. Burning a leaded-wick candle raises the level of particulate matter not just near the candle but also throughout the room and even the house. The study conducted by Shirley Wasson and her team and reported in the June issue of New Scientist suggests that just four hours of burning of one average leaded-wick candle will raise the lead levels to 6.2 microgrammes per cubic metre (µg/m3) in the room with the candle and to 2 µg/m3 throughout the rest of the house. The US National Air Quality Standard for lead set by the Environmental Protection Agency (EPA) is 1.5 µg/m3. Since 1992, US import of lead candles has risen by 800 per cent. More than 3 million lead wick candles are sold every year in the US alone. A safer though expensive alternative would be that of using zinc instead of lead in wicks.

Asthma research
Concerned over the increase in the number of children with asthma, the US Environmental Protection Agency (EPA) and the American Lung Association have launched the Asthma Research Strategy, which would discuss future research efforts and address specific issues.

The research would be used to devise appropriate strategies to control environmental factors that exacerbate asthma. According to the EPA, the year 2001 saw around 3.8 million children being affected by asthma attack. Most of these attacks were triggered by environmental contaminants like particulate matter, smoke, air pollution, and pollen.