Profits at Biospherics Inc., a Rockville environmental research company, declined from $518,564 (71 cents a share) in 1977 to $290,536 (40 cents) last year.

Revenues, however, increased 28 percent from $2,907,564 in 1977 to $3,733,268 last year. The company explained the decline in profits by saying the 1977 earnings included a one-time gain on the sale of a product line, which added $321,441 (44 cents). Without that addition, net earnings in 1977 would have been $197,123 (27 cents), the company said.

The company also boosted its annual dividend to seven cents a share, up from 6 cents a share the previous year. The dividend is payable July 2 to shareholders of record May 18.

The firm specializes in pollution control services, laboratory research, patient education products and dissemination of information on health-related topics. The laboratory division last year began a service analyzing pesticide residue and toxic substances that grossed $424,000 in revenues and $65,000 in net operating income.

The Noland Co. of Newport News a wholesale distributor of mechanical equipment for building trades, earned net income last year of $3,525,000 ($1.43) compared to $3,471,000 ($1.41) in 1977. Sales increased last year to $259.5 million, up 8 percent from $239.9 million in 1977.

Noland chairman and president Lloyd U. Noland Jr. said the increase in earnings was not very great because of expenses of adding six new branches and higher interest rates on loans.

TransTechnology Corp. of Alexandria more than doubled its earnings for the third quarter, boosting net income to $131,000 (7 cents a share) from $48,000 (2 cents) a year ago.

Revenues of the firm, which manufactures products for the defense and textile industries, increased to $7.2 million from $6.9 million.

For the nine months ended Dec. 1, TransTechnology earned $467,000 (26 cents) compared with $451,000 (25 cents) in the same period a year earlioaver; revenues for the three quarters declined slightly to $20.1 million from $20.9 million.

Capital Holding Corp., the Louisville company that owns Peoples Life Insurance of Washington, reported its operating income for the year ended Dec. 31 increased to $76.9 million [2.67 a share] from $68.2 million $2.37 in 1977.

Life insurance sales of Capital Holding's six major subsidiaries increased to $2.75 billion from $2.44 billion, and premium income in 1978 increased 6 percent to $265 million from $250 million.

Strother Drug Co. of Lynchburg, reported a 17 percent gain in earnings and a 15 percent increase in sales for the second quarter of fiscal 1979.

For the three months ended Dec. 31, Strother reported income of $294,000 (34 cents a share), up from $251,000 (29 cents) and sales of $11.3 million, up from $9.8 million.

For the first half, the drug chain's profits increased to $561,000 (66 cents) from $504,000 (59 cents)8 and sales increased to $21.8 million from $19.3 million.