Science and Technology Current Affairs

Air pollution affects children’s memory: Study

According to study published in journal Environmental Pollution, exposure to air pollution can have damaging effects on children’s cognitive development and reduce their working memory.

The study has assessed impact of fine particulate matter (PM2.5) and black carbon— a pollutant directly related to traffic during walking commute to and from school.

Key Facts

The study findings show that 20% of child’s daily dose of black carbon is inhaled during urban commutes. These short exposures to very high concentrations of pollutants can have a disproportionately high impact on health. The detrimental effects may be particularly marked in children because of their smaller lung capacity and higher respiratory rate.

Statistical analysis of findings also showed that exposure to PM2.5 and black carbon (BC) causes reduction in growth of working memory. The interquartile range increase in PM 2.5 and black carbon levels were associated with a decline of working memory by 4.6% and 3.9%, respectively, in expected annual growth.


Bacteria can spread antibiotic resistance through soil: study

Researchers including one of Indian origin from North Carolina State University in US have found that antibiotic resistance can be passed between bacteria found in the soil. They also have found that spreading manure on ground as fertiliser can also spread antibiotic resistance to bacteria in the soil.

Reasons for spread of antibiotic resistance through soil

Bacteria contain small DNA molecules known as plasmids. These plasmids are separate from bacterias actual DNA and can pick up and exchange genes between bacteria. Thus, these plasmids in bacterias are responsible for antibiotic resistance in soil also.

What researchers found?

The researcher’s observation was based on soil samples taken from swine farm prior to and for three weeks after spreading of manure. They tested manure for antibiotic resistant strains of salmonella, a pathogen responsible for causing highest number of bacterial food borne illnesses in US every year. After sampling soil, researchers found that antibiotic-resistant salmonella bacteria were still present in manure up to 21 days after it had been spread. They discovered that particular plasmid associated with antibiotic-resistant salmonella from manure which weighed around 95 kilo-base (kb), was turning up in different salmonella serotypes from soil samples and every serotype with plasmid 95 kb was now resistant to antibiotics.

Antibiotic resistance

Antibiotics are medicines used to prevent and treat bacterial infections. Antibiotic resistance occurs when bacteria change in response to use of these medicines. Antibiotic resistance occurs naturally, but misuse of antibiotics in humans and animals is accelerating the process. Poor infection prevention and control further accelerate it.