SMOC heeft meerdere malen aangegeven dat de concentratie zwaveldioxide (SO₂) benedenwinds het Isla-terrein bij de wereldtop hoort; in negatieve zin welteverstaan. Het is dan ook bekend dat veel mensen met gezondheidsklachten kampen. De WHO zegt hierover: 

,,SO₂ can affect the respiratory system and the functions of the lungs, and causes irritation of the eyes. Inflammation of the respiratory tract causes coughing, mucus secretion, aggravation of asthma and chronic bronchitis and makes people more prone to infections of the respiratory tract. Hospital admissions for cardiac disease and mortality increase on days with higher SO₂ levels. When SO₂ combines with water, it forms sulfuric acid; this is the main component of acid rain which is a cause of deforestation.”

Recent is er aangaande SO₂ een nieuwe zorg bijgekomen. In het bekende wetenschappelijke tijdschrift Environmental Science & Technology (ES&T) leggen Chinese onderzoekers (Liu e.a., “Inverse Association between Ambient Sulfur Dioxide Exposure and Semen Quality in Wuhan, China”) een relatie tussen de concentratie SO₂ in de lucht die mensen inademen en de kwaliteit van sperma. Des te hoger de concentratie SO₂, des te slechter de kwaliteit van sperma. Dit baart SMOC voor de bewoners onder de rook van het Isla-terrein zorgen. Lees hieronder de samenvatting en het hele artikel hier:

,,Evidence concerning the association between ambient gaseous air pollutant exposures and semen quality is sparse, and findings in previous studies remain largely inconsistent. We enrolled 1759 men and performed 2184 semen examinations at a large reproductive medical center in Wuhan, China, between 2013 and 2015. Inverse distance weighting interpolation was performed to estimate individual exposures to SO₂, NO₂, CO, and O₃ during the entire period (lag 0–90 days) and key periods (lag 0–9, 10–14, 70–90 days) of sperm development. Linear mixed models were used to analyze exposure–response relationships. SO₂ exposure with 0–90 days lag was significantly associated with monotonically decreased sperm concentration (β for each interquartile range increase of exposure: −0.14; 95% CI: −0.23, −0.05), sperm count (−0.21; −0.30, −0.12) and total motile sperm count (−0.16; −0.25, −0.08). Significant associations were observed for total and progressive motility only when SO₂ exposure was at the highest quintile (all P_trend < 0.05). Similar trends were observed for SO₂ exposure with 70–90 days lag. NO₂, CO, or O₃ exposure was not significantly associated with semen quality. Our results suggest that ambient SO₂ exposure adversely affects semen quality and highlight the potential to improve semen quality by reducing ambient SO₂ exposure during early stages of sperm development.’’