Killer Pollution

Killer Pollution

Increasing pollution in the metropolitan cities is taking a heavy toll on our health. It has fatal impact even on unborn babies, posing a threat to future generations

By Dr Neelam Mohan

 

Children’s health is very precious to all of us. With the increasing incidence of air pollution in metropolitan cities and its adverse effect on health of children, the policy-makers are facing an extraordinary challenge. The effects of air pollution are several folds.

 

Effects on lungs

Lungs are the primary target organ of air pollution. Serious effects include inflammation of the airway, alteration of the host defenses in the form of poor mucociliary clearance, macrophages function and immune response. These effects lead to cough, exacerbation of asthma, breathing difficulties, sinusitis, nasal allergies and, most importantly, increased risk of respiratory infection.

All this leads to increase in infant and child mortality. Infants are more susceptible to injury by lung toxicants than are adults, even at doses below the no-effect level (NOEL) for adults. In the longer run, the chronic effects on the lung include increased life time risk for chronic respiratory disease including chronic obstructive pulmonary disease (COPD), asthma and lung cancer.

 

Effects on neuro development and behaviour

The developing brain is particularly vulnerable target for chemical insult. Long lasting or even irreversible developmental consequences may occur.

Persistent organic pollutants (PCBs), Polyhalogenated aromatic hydrocarbon (PHAHs) like the polychlorinated biphenyls (PCBs), besides lead mercury and magnesium has been found to be associated with neurobehavioral deficit in children. Due to hand- mouth behaviour attitude in infants and young children the dust pollution particles may also be ingested by small children besides being inhaled.

 

Autism spectrum disorders

The blood-brain barrier is not fully developed in young children, making them more susceptible to neuro toxicity. Higher incidence of hyperactive and aggressive behavior in children has been attributed to increase in air pollution.

Autism is a serious neuro development disorder characterized by impairment in social interaction, verbal and non-verbal communication, and other restricted behavior. Autism spectrum disorders (ASDs) have increased dramatically during the last 10 years. In a recent publication from California, a potential association between autism and estimated metal concentration and possible solvents, in ambient air around these patients, has been reported.

 

Effects on childhood cancer

Road traffic is a major source of ambient air pollution in urban areas, where density of population is high. Traffic-related air pollution is a complex mixture of many chemicals, of which many are known or suspected carcinogens. A high incidence of leukemia has been reported in children. Diesel and gasoline exhaust are classified by the International Agency for Research on Cancer (IARC), probably (Group 2A) and possible (Group 2B) carcinogenic to humans, mainly on the basis of animal experiments and epidemiological studies on exposed adults.

In 1989, however, a case-control study performed in Denver in the United States showed elevated risk of cancer among children living near streets with high traffic density. Benzene, one of the air pollutants, is due to evaporation from and incomplete combustion in petrol engines, as well as evaporation related to petrol stations and the refueling of cars. Occupational studies have shown that exposure to benzene causes acute myeloid leukemia (AML).

 

Effects on pregnancy

The fetus is considered to be highly susceptible to a variety of toxicants because of its exposure pattern and physiological immaturity.

A link between low birth weight, pre-term births and  intrauterine growth retardation (IUGR) have been shown with air pollution. These issues influence subsequent health status of the child, including increased mortality and morbidity in childhood and an elevated risk of hypertension, coronary heart disease and non- insulin dependent diabetes in adulthood.

 

Effects on gut, skin, eyes

There is a major concern whether immunity is altered with air pollution. Some evidence suggests inhaling fine particles, or soot, may disrupt the immune system and trigger inflammation in the gut by making it more permeable and altering its normal bacteria.

There is an increasing incidence of inflammatory bowel disease over the last few decades. It’s unclear how air pollution could contribute to gastrointestinal disease, but experts believe that bacteria may have something to do with it.

 

School absenteeism

A number of studies over the last few decades have looked into the indirect evidence that there may be an association between levels of atmospheric pollutants and adverse effects on the health of children. These studies have been based on the assumption that significant increases in school absenteeism may reflect the health effects of short-term increases in levels of pollutants.

Effects on the skin include dryness, premature aging, skin rashes, eczema and acne. Air pollution increases dry eye syndrome with increase in eye irritation, discomfort and specific issues are seen in contact lenses users.

Thus, there are a plethora of adverse effects of air pollution on our health and especially the health of children.

 

(The author is Director, Department of Pediatric Gastroenterology, Hepatology & Liver Transplantation,  Medanta Hospital,  Gurgaon)

 

Blurb: Autism is a serious neuro development disorder characterized by impairment in social interaction, verbal and non-verbal communication, and other restricted behaviour. Autism spectrum disorders (ASDs) have increased dramatically during the last 10 years.