Noise, Pesticides, and Radiation A$ S POLLUTANTS of the environment, noise, pesticides, and radiation are relative newcomers to the public ken. The three are still shadowy and dimly understood. But they are here, and they must be dealt with. Noise has been defined as "sound without value," and the intensity, variety, and clamor of unwanted, unvalued sounds have multiplied in recent times. For many, city residents in particular, the din never ceases, and it too rarely diminishes. Pesticides, created as tools to help forge a better life for man, have turned against him in many ways and have become killers of animal and plant life that they were never intended to harm. We do not fully understand their impact on man and the environment, but we know enough to find them disturbing. Radiation is potentially a more dangerous pollutant to man than pesticides. Man has tried to turn it to his peaceful benefit and has done so in several ways. But the effects of low levels of radiation are still largely unknown. The long-term and cumulative impacts of this triumvirate of pollutants-noise, pesticides, and radiation-could be harmful to man. It is therefore imperative that they and their ways become better known. NOISE Noise is everywhere, especially in urban areas, where three-fourths of the Nation lives. The roar of air and surface transportation, the general din and hum of construction projects, and industrial noise all pound against the ear virtually without ceasing. In the decade of the 1960's, the measured amounts and extent of urban noise rose significantly. And so did the social awareness of noise and the discomfort caused by it. Urban dwellers cannot escape it. They are surrounded by a multitude of noise sources in homes, offices, or places of work. Even at play they are bombarded by scores of outdoor noises. The most severe noise conditions are generally encountered in the work environment. Excessive exposure to such noise for long periods is known to cause irreversible hearing loss. It is estimated that up to 16 million American workers today are threatened with hearing damage. The worker exposed to noise during the working hours must also endure high levels of noise on his way to and from work. Furthermore at home he must listen to household appliances, noisy neighbors, and a variety of outdoor noises which surround and permeate his dwelling. Sources of Noise Pollution Traffic noise in a modern city may reach 90 decibels. A decibel is a logarithmic measure of sound. Because it is logarithmic, linear comparisons of decibel levels cannot be made. For example, a noise pressure level of 130 decibels is 10 times as great as one of 120 decibels and 100 times as great as a noise pressure level of 110 decibels. It is widely accepted that steady exposure to about 90 decibels can cause permanent hearing loss. In general, trucks, buses, motorcycles, and rail systems are the worst offenders. With automotive vehicles at high speeds most of the noise comes from the whir of tires, while at lower speeds motor noise dominates. At expressway speeds a single trailer truck can generate steady noise levels above 90 decibels. A line of trucks can produce noise levels of 100 decibels or more. The high noise level inherent in steel wheels rolling on steel rails makes rapid rail systems noisy. Subways create noise even on the streets when they cause buildings to vibrate or when the noise escapes through ventilators, but most of the noise is absorbed by the ground. *Typical A-Weighted sound levels taken with a sound-level meter and expressed as decibels on the scale. The "A" scale approximates the frequency response of the human ear. Source: Department of Transportation. Sound bouncing off the walls can raise subway noise levels to 90 to 100 decibels in the cars. The rapid growth of aviation since World War II and the development of jets have created a major noise problem in airports and the areas around them. A four-engine jet at takeoff generates 115 to 120 decibels. A measure of the resulting annoyance is that about 50 of the 140 major American airports are involved with formal complaints concerning noise, including a sizable number of lawsuits. The Airport Operators Council International estimates that by 1975, 15 million people will be living near enough to airports to be subjected to intense aircraft noise. Cities suffer from a variety of other noise sources which are rarely curbed by government. Compressors and jackhammers are major offenders. Garbage trucks, lawnmowers, and rock-and-roll music blasting out of discotheques and jukeboxes all add to the din. At home, the kitchen with its various appliances is the noisiest room. The lack of effective noise standards in building codes allows the construction of apartments and houses in which noise from the outside and from neighbors filters in. Some persons have even taken to adding a low level of constant noise of their own to reduce the annoyance of other noise. Effects of Noise Noise can have many adverse effects, including damage to hearing, disruption of normal activity, and general annoyance. Extremely loud noise, such as a sonic boom, can also cause physical damage to structures. The most common and best understood physiological effect of noise is hearing impairment—either temporary or permanent. The amount of permanent hearing loss produced by sufficient exposure to high-level noise depends on the nature of the noise, the time distribution of particular exposures, the total duration of the exposure over a lifetime, and individual susceptibility. For essentially continuous types of noise, such as that in many factories, enough research has been done to permit some statistical prediction of the risk of hearing damage. More research is needed, however, to predict damage which results from noise of a discontinuous nature. Noise is known to produce various temporary changes in man's physiological state, in particular a constriction of the smaller arteries. This can mean a speeded up pulse and respiration rate. Some medical au |