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Advances in air pollution sensor technology have enabled the development of small and low-cost systems to measure outdoor air pollution. The deployment of a large number of sensors across a small geographic area would have potential benefits to supplement traditional monitoring networks with additional geographic and temporal measurement resolution, if the data quality were sufficient. To understand the capability of emerging air sensor technology, the Community Air Sensor Network (CAIRSENSE) project deployed low-cost, continuous, and commercially available air pollution sensors at a regulatory air monitoring site and as a local sensor network over a surrounding ∼ 2 km area in the southeastern United States. Collocation of sensors measuring oxides of nitrogen, ozone, carbon monoxide, sulfur dioxide, and particles revealed highly variable performance, both in terms of comparison to a reference monitor as well as the degree to which multiple identical sensors produced the same signal. Multiple ozone, nitrogen dioxide, and carbon monoxide sensors revealed low to very high correlation with a reference monitor, with Pearson sample correlation coefficient (r) ranging from 0.39 to 0.97, −0.25 to 0.76, and −0.40 to 0.82, respectively. The only sulfur dioxide sensor tested revealed no correlation (r r = 0.99) between identical sensors but moderate agreement with a reference PM2.5 monitor (e.g., r = 0.65). For select sensors that had moderate to strong correlation with reference monitors (r > 0.5), step-wise multiple linear regression was performed to determine if ambient temperature, relative humidity (RH), or age of the sensor in number of sampling days could be used in a correction algorithm to improve the agreement. Maximum improvement in agreement with a reference, incorporating all factors, was observed for an NO2 sensor (multiple correlation coefficient R2adj-orig = 0.57, R2adj-final = 0.81); however, other sensors showed no apparent improvement in agreement. A four-node sensor network was successfully able to capture ozone (two nodes) and PM (four nodes) data for an 8-month period of time and show expected diurnal concentration patterns, as well as potential ozone titration due to nearby traffic emissions. Overall, this study demonstrates the performance of emerging air quality sensor technologies in a real-world setting; the variable agreement between sensors and reference monitors indicates that in situ testing of sensors against benchmark monitors should be a critical aspect of all field studies.

The Kavar Village health worker project recruited local men and women and trained them to serve as health workers with family planning as 1 of their responsibilities. 14 months after the workers were deployed in this rural project (in May 1975) a survey was conducted to determine their effect on family planning knowledge attitudes and practice. The 16 project villages were compared with matched control villages. In the health worker villages 28% of married women aged 15-44 were using contraceptives compared with 15% in control villages (p less than .01). In every age group except the 40-44 age group health worker villages had higher contraceptive use. Maximum impact seemed to be among women aged 25-34 whose use was 33-39% compared with 14-20% in control villages. The health worker villages also had a slightly lower termination rate. Both sets of villages had more than 90% of married women responding they knew 1 or more contraceptive methods. However health workers had a significant effect on knowledge about the pill. Most of the married respondents in both sets of villages approved of contraception either completely or with qualifications. Sex of health worker did not appear to be significant. The auxiliary health worker is called a viable means for developing countries to upgrade the health and living conditions of rural populations. An important part of this maternal and child health and lowering birthrates. This survey shows health workers are well-equipped to do this.