Table 1
Overview of PM2.5 and PM10 annual average data at South African Ambient Air Quality Monitoring Stations at 50% data availability (South African National Ambient Air Quality Standards (NAAQS) current limit values for annual averages: PM2.5 = 20 µg/m3; PM10 = 40 µg/m3).
| PM2.5 | PM10 | |||||
|---|---|---|---|---|---|---|
| PROVINCE | STATIONS PER PROVINCE* | MEAN ± STD DEV | MEDIAN ± IQR | STATIONS PER PROVINCE* | MEAN ± STD DEV | MEDIAN ± IQR |
| Eastern Cape | 4 | 9 (4) | 11 (2) | 5 | 21 (9) | 23 (8) |
| Free State | 5 | 34 (8) | 32 (8) | 5 | 70 (25) | 59 (36) |
| Gauteng | 15 | 35 (18) | 32 (11) | 25 | 59 (25) | 55 (23) |
| KwaZulu-Natal | 11 | 19 (13) | 17 (5) | 14 | 32 (13) | 28 (17) |
| Limpopo | 8 | 18 (13) | 14 (7) | 8 | 39 (19) | 32 (24) |
| Mpumalanga | 22 | 23 (8) | 22 (8) | 26 | 51 (21) | 50 (26) |
| North-West | 4 | 25 (20) | 14 (12) | 4 | 44 (18) | 42 (36) |
| Northern Cape | 1 | 4 (–) | – (–) | 1 | 7 (–) | –(–) |
| Western Cape | 4 | 10 (5) | 8 (4) | 10 | 30 (9) | 31 (11) |
[i] * Number of stations which met the > 50% data availability threshold at least once over the period. Not all stations had data every year.
Figure 1
Scatter plots of average annual (A) PM2.5 and (B) PM10 and CLP birth prevalence per 1,000 live births from 2006 to 2020. The dashed blue vertical lines represent the current South African NAAQS of 20 and 40 µg/m3 for annual PM2.5 and PM10, respectively.
Figure 2
Location of all CLP cases in our dataset overlaid by the findings of hot and cold spots of CLP birth prevalence per 1,000 live births by district municipality. The table for CLP birth prevalence for each district municipality per 1,000 live births is given in the Supplementary Material.